I suggested putting the tower in the center of the main gun; even if you didn't change the tower design, it would help explain why the Emperor's tower is sitting on top of essentially an exhaust port to a reactor with an open top. Also made the suggestion that either the Emperor derives some power (or high) from technology or in some strange way the DS laser is partly powered by his attachment to the DSOF.
I still think it would be cool to have the Emperor be the one to take out (or help take out) the DS reactor - as in, when the Falcon shoots, it can't quite get through the inner reactor shield. When Darth throws the Emperor down, you could play off of the end of TRON and show the Emperor's body falling into the reactor, causing the shield to come down or start to destroy part of the reactor, which would then chain react into bigger explosions, until finally you show the reactor topple over and explode.
This would in turn give the Falcon the needed time to escape (can't show the reactor topple, fall and then explode behind them, as the whole DS would go up instantly, destroying everthing around and inside it, including the Falcon).
re: Leia and the Ewoks:
don't know if that would be too much of a problem (other than the lack of comments from Luke and Co.), being that if she's been missing for some time, that allows her the time to change hairstyles and clothing. It is only if she looks one way one minute and then completely different within a minute or two.
You know, just for "s and gs", someone should make a short prequel edit where people are conversing with Padme and everytime the camera cuts back to her, she is in a different get-up (hell, even take clips from other Natalie Portman movies - you could have Hayden speaking to her and cut to a scene from LEON, goes back to him, scene from V, etc).