Return of the Jedi/WMG

R2-D2 mind-controlled the Death Star, wanting to destroy it more awesomely
This would explain why Luke, who was a great pilot, was on the strike team instead of piloting an X-wing. R2-D2 begged him not to, not wanting to destroy his own project in such a lame way as torpedoes, and probably intending to self-destruct it in an awesome way. Luke agreed, but the Rebels still went ahead with their own (generic) plan.

The ending celebration montage takes place over several years
As someone pointed out on the "Just Bugs Me"-page, there's no way Coruscant - The Imperial Capital - would be in open celebration, only hours after the destruction of the Death Star and the death of the Emperor. Riots, stormtroopers everywhere, etc, seems more likely. The solution? The different scenes in the montage doesn't take place during the same time period. The shots of Luke and the others on the moon of Endor are obviously set only hours after the destruction of the Death Star, but the celebration on Coruscant could be months, or even years into the future
 * It's actually possible. See, for example, the initial uprising in Libya - Tripoli rose up, before Gadbastard sent in the aircraft. And a technologically-advanced society would be able to know that Palpatine was dead. The EU also states that that celebration ended with a brutal crackdown by the stormtroopers...

"Last of the Jedi will you be" is Yoda-speak for "You will be of the last Jedi"
So, more Jedi do exist, but there are so few of them. This might help reconcile all the Jedi that survived without making Yoda either a liar or misinformed.
 * "I am the last surviving member of the Grand Council, not to mention the most senior. So if you do this, you'll still be a jedi, unlike those other jerks who use the force and play with lightsabers without my blessing." Bloody "From a Certain Point of View". Alternately, replace the period in the original statement with a rhetorical question mark.
 * But doesn't "a liar or misinformed" describe every last Jedi we see on-camera in the entire series?
 * I'm sorry, but this WMG is not very grammatically sound. You have the clause "last of the Jedi", and then separately from that the expression of Luke being, the proper word order being "you will be" and Yoda's way of speaking going "will you be". Were Yoda to say what you were suggesting, the way he'd put it is, "Of the last Jedi, you will be," or, "Of the last Jedi, will you be."
 * this troper always thought that it was supposed to be a question "will you be the last of the jedi?" makes perfect sense in that context.
 * Except there are no more Jedi. Force users, sure, but not actual Jedi.
 * In a novel, Ben tells Luke he's not the last Jedi, but "the first of the new".

Ewoks are eaters of their defeated enemies.
The Ewoks were completely ready to roast up Luke, Han, and Chewbacca for feast to honor their new god. While they get out of this unscathed, at the end there are quite a few Imperial helmets being used as drums, which makes you wonder what's the main course in the feast to celebrate their defeat of the Empire.
 * During the celebration, I sure hope our heroes warned their rebel allies to stick to the salad.
 * This begs the question: are we talking already dead ones or live ones? 'Cause the Rebels took at least fifteen guys prisoner when they finally took the shield generator. I just can't see the Rebels murdering prisoners. So I think they could've given the Ewoks the numerous already killed Imperials, but I doubt they'd turn over the ten to fifteen guys they caught outside the generator.

Palpatine threw the final battle.
If you watch the battle among Luke, Vader, and Palpatine in the second half of the movie, you come to realize that Luke would have turned to the Dark Side instantly if Palpatine had just shut his mouth. This could have been Obfuscating Stupidity and the Villain Ball that he was carrying for the entire movie, or it could be that he had had enough of the Dark Side and wanted to die. (Then again, given how he spends the entire EU trying to come back, it was probably just the Villain Ball.)
 * Or he's just lost it. He's not exactly very bright in that movie.
 * I reject this for the same reason I reject the theory that he threw his fight with Windu: he's just plain too proud. A master manipulator like him could easily find a way to accomplish the same things without having to suffer humiliation or harm, and he would never allow himself to end up on the short end of the stick to the pitiful likes of...well, anyone, if there's anything at all he can do about it.
 * Palpatine didn't want Luke to fall to the dark side. He wanted Luke to fall to the dark side and become his apprentice. The last fight with Vader started with Luke attacking Palpatine and Vader trying to stop him. In other words, Luke is fighting Vader in defiance of Palpatine. If Palpatine said nothing and let Luke kill Vader, then Luke is killing Vader (Palpatine's apprentice) in defiance of Palpatine. He may have fallen, but he would have become a Dark Jedi rival to Palpatine. Even if Palpatine was certain that he was more than powerful enough to destroy Luke in that situation, in the end he would have no apprentice. So he had to interrupt when he did. It was a test of Luke's loyalty. Now, if Luke kills Vader, right after Palpatine tells him to, then that act would be one of obedience and submission to Palpatine. Only then would Palpatine be sure that Luke is falling and becoming his loyal apprentice. If Luke remains defiant and refuses to kill Vader, then Palpatine would kill Luke, and he gets to keep Vader alive as his apprentice. There was nothing, nothing, stupid about Palpatine's actions and words there. It was all deliberate and consistent with his plans to that point. His only mistake was not anticipating that Vader would turn on him for Luke's sake. His arrogance was in his assumption that his manipulation and breaking of Anakin Skywalker was complete and irreversible.

The Sarlacc is a larval space slug.
Back in The Empire Strikes Back, we saw a gigantic worm-like creature which tried to eat things and had a breathable atmosphere inside it, in an asteroid field that looked kind of like the results of the destruction of Alderaan (so it might originally have been on a planet). In Return of the Jedi, we see a smaller worm-like creature that tries to eat things; it was on a planet with a breathable atmosphere, no vegetable life, and a lot of Dune references. In Dune, the sandworms provided the atmosphere of Arrakis, and the atmosphere of Tatooine has to come from somewhere.

Also consider that the Galaxy Far, Far Away is home to a very large number of very nasty organizations, all of which are eager to inflict the most horrible deaths they can on their enemies, but only one of them, and evidently not one that's exactly on the cutting edge of things like scientific knowledge and military equipment, uses the Sarlacc for executions.

Thus, the Sarlacc is a larval form of a space slug, and space slugs are terraformers originally created by the Rakata or one of the other species of Precursors that the Galaxy Far, Far Away is positively swimming in. Like a space slug, it eats anything that gets close, but it digests things over a normal, less-than-a-thousand-years timeframe -- it needs the biological molecules. (It can probably also handle metals and use those for structural purposes as well; it must get its energy from an internal cold-fusion reactor or thereabouts, as neither the Sarlacc nor the space slug had a diet that would provide enough energy for its extreme activity level.)

Ask any xenobiologist, and he can tell you as much -- and can probably give you a DNA sample and tell you where other creatures of the species are located, how long they take to mature, how long it takes a mature one to transform a desert wasteland into a comfortably habitable planet, and whether they die after the end of their Roaring Rampage of Terraforming or whether you have to kill them.

Jabba, of course, was too clever for the xenobiologists and asked the local Jawas instead, explaining why he's the only person in the galaxy who throws people into the Sarlacc as opposed to inflicting some other, more conventional, form of horrible death.

Its form as depicted in the original version of Return of the Jedi is a very "newly-hatched" stage, where the characteristic space-slug mouth is still developing; its form as of the Special Edition (which was what Lucas wanted to do to begin with, although he didn't have the budget) is a later-stage juvenile space slug.

The Ewoks are the most bad-ass race in the Galaxy.
They're willing to take on enemies with far more advanced weapons, like AT-S Ts and blasters, which takes guts. They are able to create huge suspended villages and set up effective traps in a short amount of time, which shows good planning and discipline. They aren't afraid to use unfamiliar technology, which makes them adaptable. And finally, there appears to be thousands of the little buggers, which could indicate rapid breeding. If they ever get off planet, they might start their own empire.
 * Take note that they do appear to be the only species in the entire galaxy that understands the concept (and has the wherewithal to build) railings.

The Sarlacc is actually an Eldritch Abomination that serves as a portal to Hell, and the people telling otherwise were making the whole thing up
Hence why the people who falls in there will be in great pain, for a thousand years, if not eternity. On the other hand, it's not just a thousand-years digestion, it could be worse....
 * Indeed. Could be stabbed.

The Ewoks are the Furlings of Stargate fame.
Think about it. The Ewoks created huge villages suspended from the trees, and fended off a troop of Imperial forces, armed with slingshots and rocks. A species with that much intelligence and skill could have easily been one of the four races if they had a stargate.

Simply Striking Down Palpatine Wouldn't Have Turned Luke to the Dark Side...
...and Palpatine is fully aware of that. Killing Palpatine would've effectively been something heroic, it would have saved the lives of millions, so it was only justified. However, Palpatine is a Magnificent Bastard, after all. Once he directly points out that he's defenceless (except for the electricity Luke probably doesn't know about) then it stops being outright heroric. Palpatine then messes with Luke's head. If Luke did strike Palpatine down, he would've gone to the Dark Side because he believed he'd fallen to the Dark Side, due to misplaced guilt and all that.

Imagine if Luke wasn't so Lawful Good and was instead an Anti Hero, and simply went "Shut UP Hannibal" and force pulled the lightsaber and chopped him down then and there. Would that really have dragged him to the dark side on its own?
 * Presumably if he tried at that point, Vader would have intervened, and the fight between them would have just started earlier (and if Vader didn't intervene in time, Palpatine surely could have force pushed or lightning'ed Luke to defend himself). Palpatine's plan was probably to provoke Luke into aggression, get him to start a fight, and let it snowball from there.

And of course, by making it seem like such a wrong thing to do, Palpatine pretty much guranteed that Luke wouldn't kill him. Fortunately, Vader interveened and killed the Emporer.

anakin brought balance to the force by killing palpatine
the sith is not what was causing the imbalance. it was palpatine. so, in the death of palpatine, the force was brought into balance
 * Actually it was the Sith, basically the idea behind the prophecy is that the Sith and the Dark Side is a cancer upon the force, a balance isn't an equal amount of Sith and Jedi, it is the complete absence of the Sith. Anakin killed his master and in so doing died himself, he brought balance to the force yet was at the same time one of the things unbalancing it since he was a Sith, as there are only two true Sith at any given time, of which Palpatine was the master and Anakin the apprentice. His self-sacrifice killed his master and himself and brought balance, the prophecy wasn't misread, it simply came at a time when it wasn't expected.
 * Or, it was balanced because Palpatine was the last Jedi or Sith in the galaxy. Remember, Yoda told Luke he wouldn't be a Jedi unless he killed Vader, and he didn't. The Jedi were the action, and the Sith were the equal and opposite reaction. Both authorities are now eliminated.
 * Nope, Yoda said he wouldn't be Jedi unless he confronted Vader, which he did. Plus Luke actually says "I am a Jedi."

Palpatine lied about being unarmed
In Revenge of the Sith, when Mace and several other Jedi came up to his office to arrest him, he had his lightsabre pop out of some kind of springloaded sleave holster and went on the attack. It would hardly be a stretch of the imagination for him to still use that lightsabre and its rig, since he would be able to defend himself if a wouldbe assassin defeated his elite bodyguards (Vadar can't be at his side all the time, you know). Why he didn't whip it out and use it is the real puzzler though...
 * Why would he? Vader was there and Luke fighting Vader was key to the "turn him to the Dark Side" plan. When Vader grabbed him he didn't really have time to grab his saber and it wouldn't have done much good anyway.

Vader threw the fight with Luke because he couldn't bring himself to kill his own son
The only time you see Vader really try to kill Luke is in A New Hope during the Trench Run, and he doesn't even know who Luke is at that point. When the Emperor tells him that "I have no doubt this boy is the offspring of Anakin Skywalker." Vader's first thought is how to turn Luke, so that they could overthrow the Emperor and end the war, ruling the galaxy as Father and Son. Him fighting Luke at Cloud City was a test, to see what his son's strenghts were, and to try and sway him to Vader's side. Cutting off Luke's hand was an accident, which is why Vader stops attacking him at this point in the duel and instead reveals the truth, hoping to finally sway Luke to join him in overthrowing the Emperor.

Come Return of the Jedi, Vader is reluctant to bring Luke to the Emperor, but does so mostly out of hope that Luke will join him. His comment "It is pointless to resist" is him telling Luke to give in to his hatred of the Emperor, so that they can kill him and become the new rulers. When Luke makes a move to kill Palpatine, Vader steps in to stop Luke from turning to the Dark Side because he knows that Luke, having been swayed by Palpatine, will merely replace Palpaine rather than join with Vader. Notice that never once does Vader even come close to killing Luke, and Luke even manages to get the upper hand a few times (Force Kicking Vader down the stairs). When Luke hides in the shadows, Vader once again tries to talk him into joining him in striking down Palpatine ("Give yourself to the dark side. It is the only way you can save your friends.") His talk of turning Leia to the Dark Side is a furtherance of his goal of having the Skywalker family united and ruling a peaceful galaxy. When Luke attacks him this time, he cannot fight back without hurting/killing Luke, which leads to him losing a hand and almost dying at Luke's hand. If you look closely when Vader is lying on the catwalk, you can see him moving his hand as if to say, "Calm down, control yourself," to Luke, who is still wanting to kill him at that moment. He is trying to calm his Luke because killing Vader would leave Luke to be trained by Palpatine i.e. not part of the Vader Master Plan. In the end, he turns back to the Light Side and kills Palpatine once he realizes that this is a replay of the moment that he turned to the Dark Side: a Jedi is about to be killed by Palpatine right in front of him, and he has to make a decision who he will side with. This time, he chooses to reject Palpatine in order to save his son, and dies for it.
 * I don't believe Vader taking Luke's hand was an accident. You must remember that limbs are easily replaced in this universe (comparable to fixing a broken arm). Luke was not going to stop fighting until he died or was disarmed. At least two times, Vader basically stopped fighting to tell Luke to give up and that he's been beaten, only to piss off Luke more to keep fighting. Couple that with the hit that Luke scored on him (shoulder, I believe), Luke was more powerful and determined than Vader thought. Taking his weapon (and his hand) was the only way to stop the fighting that would end up with one of them dead so that Vader can try to convince Luke to join up.

Ben and Yoda lied to Luke specifically so he could kill Vader.
While Yoda tells Luke that they lied because they didn't think he could stand the truth, he was still lying. When he and Ben told Luke that Anakin was utterly lost to the Dark Side, they were lying. They knew that Vader might still have some spark of good left in him, but they didn't want that spark revived. Why? Because they didn't want Anakin redeemed.

After years of brooding over their failure and mourning their dead friends, Ben and Yoda wanted Vader punished for his crimes. They wanted him dead and rotting in Sith Hell, not redeemed by the Light Side and getting into Jedi Heaven. So, they lied to Luke so that he'd feel righteous anger (though not Dark Side anger) towards his father's supposed murderer, then go off and cut the armored buzzard dcwn without a second thought. That's also why they didn't want him to try to save his friends: more programming for their cause and more reasons to hate Vader's guts.

Fortunately for everyone, Luke saw the truth and took the right path, resulting in Anakin's redemption, Palpatine's death and freedom for the galaxy.
 * In a less callous judgement of them, they probably did a risk/reward analysis and decided that even if Anakin did supposedly "have a spark of goodness left in him", Vader betrayed their order, slaughtered children, helped enslave much of the galaxy, and served as Palpatine's attack dog for nearly two decades, so that spark would be extremely difficult to bring out. Luke was too valuable to risk doing what they thought was likely a pipe-dream.