I have some extensive edits in mind for RotJ as well. In addition to all the obvious concerns with the Ewoks is their apparent lack of motivation. What makes them want to join the fight against the Empire? The Radio Drama, which I think is in fact superior to the movie if for no other reason than addressing many of its unanswered questions, has C-3P0 explain in detail the Ewoks' decision making process. Anthony Daniels of course does the dialogue, so it would be an easy edit. I laid it all out in a word document which I seem to have misplaced (go figure that one), but still have all the key lines from the RD I wanted to use written down. When I get a chance I'll reconstruct my script and post the exerpts in question. It's also interesting to note that unlike in the film, the residents of the forest moon are called Ewoks by name in the radio drama.
Replacing their childlike theme and cute sound effects might also go a long way into making the Ewoks as reasonable an adversary you can expect out of a two foot tall teddy bear. I've never seen the Ewok movies, but if their footage can enhance the Battle of Endor I say use it. TM knows a lot about using fullscreen footage for widescreen purposes. And I had never noticed the Ewoks NEVER BLINK. That IS creepy.