I think the Leia/Luke relationship should be kept, but perhaps smoothed out a bit. Assuming good old Georgie was telling the truth for once, he had planned to spread the OT over six movies, and Luke wasn't supposed to find out that Leia was his sister until the second last movie or so, meaning the storyline would be able to play out a bit more naturally. Because it was only done in three movies, I think that makes it a bit more awkward, so that's probably why so many people have a problem with it.

I like Bingowings idea about the Death Star quite a bit.