The Blues Brothers/Headscratchers

The entire scenario involving Bob's Country Bunker and The Good Old Boys:
 * First, either Bob, his wife or one of his employees booked The Good Old Boys, so they should have known that Jake & Elwood were not them.
 * Perhaps they were booked through the Good Old Boys' management rather than in person? Alternatively, if it was an employee who did it, then presumably that employee wasn't working that night.
 * That makes sense. Bob doesn't seem to recognise the Good Old Boys when they show up.
 * Second, The Good Old Boys appear to be a fairly successful band (they had their own custom tour bus) but they were booked to play a podunk bar in Nowheresville for a measly $200.00?
 * They could be a once-big act which have fallen on hard times; the tour bus is just a remnant of The Good Old Days.
 * Bob's place might be one of those venues where every act in the scene plays at least once no matter how big they get.
 * They could also just be pretentious and have the bus as a way of making themselves seem bigger than in fact they are.
 * Third, Bob tells Jake & Elwood that they played some of the best music they'd ever had that night. Why on Earth would Bob try to make them pay another $100.00 for the $300.00 in beer they drank when he must have made way more than that from his customers who stayed and enjoyed the music?
 * Because Bob's very miserly and loves money more than he loves good music.
 * Businessmen that just throw away a hundred bucks at any opportunity don't stay in business very long. They drank $300 worth of beer.
 * Fourth, the Good Old Boys show up several hours late, after the bar was closed, without having called ahead to let Bob know. Not only were they late, they had missed their entire gig! Where were they?
 * And why were they angry at the Blues Brothers? Since they missed the gig, they weren't getting paid anyway so the Blues Brothers didn't steal their money or anything.
 * Because they're aggressive assholes.
 * And the Blues Brothers did pretend to be them and steal their gig; late or not, it's the principle of the matter.
 * They do acknowledge that they were very late, so they probably just got lost or burst a tire or something. It was extremely lucky but still, Mission from God.
 * Fifth, why is Bob angry at the Blues Brothers, who showed up and played, and not the Good Old Boys, who didn't arrive until after closing? If Jake & Elwood hadn't shown up, Bob wouldn't have had a band, and he would have looked like an idiot.
 * Because they stiffed him out of money they owed him and -- in conning themselves into a job -- made a fool out of him.
 * Why do the hicks keep throwing bottles even at songs they like?
 * Because they're hicks.
 * If Elwood's liscence was suspended, why couldn't Jake just drive? I mean, I'm sure he could. Then they wouldn't have run into all that trouble.
 * He's been in jail for a few years and only been out for a day or so. His license was presumably expired or revoked and he hadn't gotten a new one yet.