Here are two: 1) Cool it with the CGI, it doesn't hold up well if you abuse it and will look like ass after a year or two. 2) Let merchandising do whatever they want except influence the film in anyway way.

Those are the things that pissed people off the most. The general public didn't give a shit about the scientific/mystical "The Force" issue. They cared about pod racing having no fucking relevance to the movie and jar-jar looking like ass in addition to being annoying.

(The primary issue of shit dialog is probably already fixed, just by having new people on the job.)