Schlock Mercenary/WMG

Petey's apparent abandonment of the Toughs was All According to Plan

 * The Toughs' well known association with the Fleetmind was drawing too much attention from the UNS, and Petey is rather fond of them. He needed a way to keep them safe while he didn't need them, and appearing to sacrifice them to UNS control was the best way to do it. Since he's capable of messing around with a Battleplate's AI, as well as providing the technical material for the nanite plans, he probably hid a switch in the false memories of Tagon's crew to restore their real memories.
 * Jossed, he said he can't restore their memories, just flag false ones.
 * Nope. He can fully restore previous memories. It just took him a bit longer.
 * So that'd make it double-Jossed? Jossed and Jossed again?

Petey has or is building a second Tagon's Toughs.

 * Think about it: Tagon's Toughs are too useful to the Fleetmind for Petey to just let them go. And we have at least four persons at large that were once Toughs: General Karl Tagon, to command; Timeclone!Kevyn, Resident Mad Scientist; John Der Trihs, acknowledged master tactician; Shep, grunt and founding member. Plus, Doythaban could still be out there (remember the ancient Bene Gesserit axiom: they're not dead until you've seen the body, and even then, don't be too sure.) This implies, of course, at some point the twain shall meet, and likely recombine.
 * Jossed
 * Jossed

Lota is planning to save the Credomar populace from a ticking bomb.

 * Lota is not planning to destroy the place or take it over by moving everyone else out. Lota has discovered that there is an imminent danger in staying on Credomar, but cannot just tell the people to evacuate for some reason. Or possibly they'd be in more danger if they ran now. But once Lota has the teraport stuff installed, it'll be a snap to move them all off to a secure location. When Credomar blows up or gets taken over by baddies or gets turned into a superweapon or gets pushed into the sun, the people will be safely out of the way.
 * And this one has officially been confirmed!

Why did Tag not come back online? Petey stole him.

 * I am probably getting part of how AI works in the Schlockverse wrong, but bear with me. Petey and Tag got along very well the few times they encountered each other, and the latter even managed to spot Petey's meddling where most everyone else couldn't. I don't see Petey wanting to watch such a brilliant mind to go to waste, so if it was possible he might have spirited Tag away to let him join the Fleetmind.
 * Tag isn't gone - Tagii was grown from Tag's gestalt. Para could have rebuilt Tag as he was, but he would still have an open exploit (force Tag to act independent of Tagon's orders, break the AI in the middle of combat, bad guys win.) All of Tag is still there, and I suspect that Tagii will have all of the quirky humor and tactical genius Tag had - we just haven't seen Tagii in action yet.
 * Given her one-off comment to Tagon along the lines of 'it's a pleasure to meet you from a new perspective', I'm starting to think this may be the case as well. Would be nice if we could get some Word of God on this, though . ..

Petey and LOTA will go to war for control of the galaxy.

 * Petey has one Ultimate Weapon (which harnesses the energy of the galactic core), LOTA has the other. And though LOTA has no target as of yet, LOTA says "every weapon advance, no matter how horrible, is inevitably followed by a situation in which that weapon must be employed." LOTA's got the galaxy's largest Chekhov's Gun, and LOTA knows it.
 * One problem (for Petey at least); all of the galactic core's power is currently getting thrown at the Paa'nuri in Andromeda.
 * And the Chekhov's Gun has since been fired. Of course, there's nothing to say it isn't actually a Chekhov's Boomerang...
 * Unlikely. They both seem smart enough to know that a galaxy-wide war between A Is could only have one conceivable outcome: the beginning of the reign of Empress Para Ventura.

The creator of the Laz'r'us nannies used them on himself

 * It was briefly mentioned that his corpse was missing bits when Doythaban recovered it. And there had to be some way that he uploaded his memories into the magic cryokit.

Petey is following his programming
He has realized that the Ob'enn are on a path to self-destruction, so to save them he has to conquer them.
 * During the short arc where the Tough's were fighting the Ob'enn for him he said that POWs were being taken to a multi-species resort habitat to try and form a less xenophobic culture.
 * He was hijacked by a group of Ob'enn who wanted to stop the war of the Tause system a few centuries ago, maybe he gave their ideology a few thoughts between simulations of the probability that he was haunted.

Brad will be back.

 * Brad is either alive right now or will be revived sometime in the future, since Petey used the immortality nannies on Tagon's crew.

Kathryn will join the Toughs

 * Because there's not enough dry sarcasm yet!
 * Confirmed. She and Trevor join as intelligence analysts some time between the start of the epilogue of book 14 and the start of book 15.

The current arc will end with the Toughs wanted... for bigamy.

 * According to Word of God, their (actual, forgotten) marriage is likely on record. Precedent set by gate-clones will have expanded the definition of "bigamy" to include two marriages to the same person, which will get them banned from taking UNS contracts again.
 * This presumes that in the intervening thousand years that there hasn't been some form of legal recognition for polygamous relationships, even if its only been precipitated by the Gate-Clone issue. It also runs into the same problems that the Tough's once faced in an alternate timeline. Getting proper ID from the Gav's.

Colonel Jacksmouth is still alive
Despite being shot in the head. Y'see, Xinchub stated that Jacksmouth and he are both immune to mindripping. This is the same (or a very similar) mechanism that kept Xinchub alive despite being decapitated. So Jacksie probably has gone through the Lazarus project and thus is nigh-invulnerable.
 * Given that his corpse was tossed into space that may not be a good thing. Though Petey may have retrieved him before sending the Toughs after Xinchub (which would explain how he developed those non-human nannies so quickly).

Kathryn will become the Toughs' new archenemy.
She's been built up too much over the last two books to be left by the wayside, or even just added as another grunt. Book 6 ended with a pretty major paradigm shift with the formation of the Fleetmind and Petey's war with Andromeda; what will book 12 end with?

Kathryn will eventually marry Tagon.

 * Word of God was that we'd meet Tagon's wife in the current arc...
 * Which arc was this?
 * If it was this arc, almost certainly Jossed by the 7/24 update.

Major Murtaugh will eventually marry Tagon.

 * See the above strip.

The Hencke/Ventura scale is named after Para

 * Or rather an ancestor. (Para is around eighteen years old, and the scale was mentioned many years ago.)
 * Not that many years ago, and it's entirely possible that a prodigy with such skill in robotics would be renowned since at least 2 years ago, if not longer.

Para
Max Haluska's favorite speech code is the "Aunt Amy Uncle Bob" code, which was lampshaded (for lack of a better term) by Kathryn. When he tries it again, here, Para responds "No relation",
 * This would also explain the behavior of the Morokweng ship-bot --.
 * More confirmation: Max Haluska suborned Tarfeather with nanites hidden in a tooth. Later,
 * Para's "friend" who had the pull to grant citizenship to the Tarnation
 * How is this even WMG? She clearly works for the UNS.
 * This part is Jossed:.
 * Para, though working with at least one UNS faction, will end up liking the Toughs enough that she colors her reports and only reports enough information to keep her UNS employers from guessing her new allegiance.
 * Confirmed in book 13.

There are far more than 70 Maxims

 * Part of the original joke prior to the Franklin Covey–induced retcon was that although the book was called the "7 H*bits" there were clearly far more than 7 rules included. Having more than 70 maxims would maintain the original joke.
 * If the author continues to release Maxim-themed calendars, and stops at 70, this would leave two blank pages in the 2017 calendar. Being famous for planning ahead, I'm sure that this is something that has crossed Howard's mind at some point, and having more than 70 maxims would be one possible work-around.
 * Alternately, there could turn out to be fewer than 70 maxims, inverting the original joke. The highest-numbered rule revealed in canon is #37.

Int-Aff-Int was in on the Schuul plot to start a civil war in the UNS
This doesn't fit their characterization as A Lighter Shade of Grey than most of the UNS intelligence community, but it would explain why they not only were desperately trying to buy warships just before book 15, but were trying to buy them outside the UNS's sphere of influence.
 * The deal was part of the not-so-secret offer. They just wanted to secure whatever share they could. As to secrecy, there are two reasons:
 * by definition, Internal Affairs means their adversary is the rest of UNS agencies and
 * good old Plausible Deniability.

The ghosts thing was indeed just sewer acoustics, but done intentionally
It just seems the most probable. The evidence against it is that until overloaded, sewage system worked fine, but this could point to either miscalculation, intended delayed effect or being done at the time of the massacre or clogging.
 * A. Some engineer had morbid sense of humour, or maybe someone managed to subtly infect fabbers in the Ob'enn dock. (from /Headscratchers page)
 * B. Petey got a little crazy or desperate before the ghost thing, so he tweaked the sewage system (not too complicated for a high-end AI with a bay full of idling fabber bots nobody watches or will audit) as a psychological warfare operation against the traitors, then removed the memory of the deed so that he won't be forced to reveal or undo the sabotage. Maybe even weakened safeguards against further insanity. (from /Headscratchers page)
 * C. One of the dead guys (from either group) was infected with an advanced nanobot swarm. Not inconceivable, seeing things Laz'R'Us swarm did. After being flushed, the swarm rigged the sewers to produce spooky sounds, then destroyed evidence of tampering, including itself.
 * C1. It was supposed to do exactly this, after being excreted normally and requisitioning small amounts of materials from the sewage, so that it won't be detected for a while. The corpse clog allowed it to build up very fast without being noticed.
 * C2. Someone expected the body to undergo such improper disposal, thus knew of the plot.
 * D. As (C), but it was intended for delivery via the gate-clone as a part of psychological warfare operation against the Gatekeepers, whether instigated by one of their own factions (they are ever plotting to the point of keeping secrets from themselves, after all) or someone who suspected what they do. Perhaps somehow linked to the Nejjat incident? If those saboteurs didn't know details, using military personnel with high clearance as the bait is a very sensible move, too.

Arc-R-Us
"Archie" resulted from a nanobot swarm with distributed AI (not unlike early Laz'R'Us swarms in Xinchub and Kevyn), used in a more aggressive attack of the same nature as above, but aimed at information gathering (which it jolly well did, collecting horns from the whole habitat).
 * A. There's no reason why the swarm could not build or hijack hypernodes, and it obviously had more than enough of opportunities to do this even before finishing (or even starting) the massacre. When the Toughs arrive, they don't detect any hypernode jamming around the habitat, so nothing would stop this. It probably finished the transmission long ago.
 * B. Whether due to evolving out of control or data loss, it became disinclined to finish mission by reporting to (or being collected by) its creators. Early on it talked raving mad, after all.
 * C. Either its creators or Gatekeeper security who noticed the problem too late may have started the chain of events leading to the Toughs capturing it and Petey getting the data.