It’s a really fun creative thought experiment. As far as not rewriting what we already have I still find myself arriving to the same place when it comes to a few details, though the events wouldn’t all unfold the same way. Jabba for example can’t just be namechecked for the first two movies and not make an appearance, we already know that’s where Han was taken and although that leaves who and what Jabba is up to interpretation we still know he is a crime lord, even from there the idea that Han in carbonite becomes a trophy is too perfect for any alternative I could come up with, the rescue is a different story.

The Emperor similarly I would still want to appear in person and show his stuff, Boba would likely have a bigger supporting role, same for Lando. Yoda wouldn’t die at least not so early or without another key assist. Leia would also have a larger key role in spiritually saving Luke, she would be revealed as pregnant within the movie. Luke himself would be more on his own again in a sort of monk like meditation/training state, he still needs a new lightsaber so where he went and what he was up to would be related to that as well for the first act. Ben’s ghost would call out to Leia and Vader not just Luke.

…uhh…I’m out for now. Anything else I can think of is pure spitballing…like…what if Han heard some information we missed during his torture in ESB that could be a strategic turning point in the plot by the time he’s rescued which would be a lot closer to the end of the second act?