Random idea regarding Palpatine:
One gripe I’ve heard people bring up before is Palpatine committing the “Evil Gloating” trope when he tells Rey that if she kills him, his spirit will pass into her.
Palpatine: You want to kill me. That is what I want. Kill me, and my spirit will pass into you, as all the Sith live in me.
This may have been suggested before, but I was thinking this line could be moved to Kylo’s first scene with Palpatine, replacing Palpatine response after one of these two lines:
Kylo: I killed Snoke. I’ll kill you.
or
Kylo: You’ll die first.
I personally think it would fit better to replace Palpatine repeating the “to cheat death” line that doesn’t do anything beyond being a callback. Either way, I think this change would accomplish a few things. First, we get a stronger explanation and understanding of Palpatine’s true nature and means of survival at the beginning of the film rather than the end. Second, it provides a good reason for why Kylo didn’t just immediately kill him. And third, it creates dramatic irony during the climax, because we know what is at stake if Rey kills Palpatine, but she doesn’t. So hopefully the audience would react by thinking, “No no no, Rey, don’t do it he’ll possess you!”
While I think moving that scene would be good, for Kylo’s arc, it kinda creates a plot hole… because now there’s no reason for Rey to pause on killing Palpatine. She initially is going to kill him, is given that reveal, then chooses to fake out and help Kylo. The motivation for that sequence is that she can’t kill Palpatine.