I'll restate my opinion of Fett here:
Boba has been hanging out at Jabba's palace just standing there next to Han in Carbonite for no reason really. No more bounty hunting for a year? Sure, he probably got tons of cash for bringing Jabba Han and an art piece all at once (the only thing I liked about Shadows of the Empire was Fett twisting Jabba for more money, and that only in the comics), but why would he stick around and not spend the money, or if he lives for the hunt, you know, hunting?
Every shot before he leaves Jabba's side because he senses Luke is going to try something is an insert shot with no other characters in it except for the SE shot of him hitting on a dancer for absolutely no reason.
The only things he does in the movie (not including the SE) is raise his gun at Boush, nod at her afterwards from the same position, walk up to the deck of the sail barge, fly over, shoot and miss at Luke two or three times, get hit in the jetpack (accidentally), scream (not sounding like either the original Boba voice or Temura Morrison), slam against the side of the sail barge, and roll down into the Sarlacc's mouth.
I think Fett should show up in ESB to do a bounty hunting job, catch Solo, then leave. He did his job, its nothing personal. He doesn't need to stick around, and he definately didn't need to be killed off, especially if Lucas says that he intended to have a shot of Fett crawling back out. The easiest way to have Fett not be a threat in the rest of the movie isn't to kill him, its to not have him in it at all. Maybe have him be a looming threat, because maybe he didn't get paid yet and now wants revenge on Han, or something. Lucas should have thought of that, but he changes his story all the time, I'm sure Fett was meant to be dead in the Sarlacc when he filmed it.
But that's my opinion, of course.
Another RotJ question though:
Sarlacc, with mouth or without? I know it looks kind of like Audrey II, but I honestly think the mouth thing helps with the danger instead of being just a hole with teeth. Did it need to be done? Of course not. Do I think it improves the scene? I think so.
EDIT: I forgot that Boba tries to tie up Luke with some rope, then gets knocked over.