I don’t really mind the SE material, I even think the opening to be more enjoyable that way, so I hope you’ll keep much of it, Sarlacc included.
What points do you have in mind of the intro aside from the Sarlacc?
I would say everything (the added shots of the barge going to the pit, the new door, the enhanced effets here and there, etc.), minus Jedi Rockz. For this scene both versions suck IMO, the theatrical is at least less time consuming. There might be a way to use the SE material into the original version but really I’m not sure it’s worth the effort.
As for the rest of the movies, I don’t like at all Vader’s “Nooooooooooooooo”, and I’m more puzzled about his Force Ghost. When you watch I-VI, I get it with Hayden. If you do it IV-VI, Shaw needs to be there. But the only things I really hate are the way too long ewok sequences (I always press the “next chapter” button when comes the awful tribe scene, with 3PO levitating and so on) and the curious ending with them dancing. I don’t really want to remove them entirely, but trimming the worse parts would be great. With Han’s silliness removed as well, Ep VI could be almost a very good movie, not just a “fine but partially missed” conclusion.