I think there is some value in giving Rey these darkside abilities, since Palpatine or not she is struggling with some dark emotions in TROS. The lightning especially feels very right for Rey, and I like it even more if it is unconnected with her heritage because it feels organic to her struggle with Kylo.
That’s how I feel yeah. One potential solution is taking a page from DOTF and making it purple lightning.
The Death Star door never really occurred to me. You could probably think of some explanation. What worries me more is Leia’s line “Never be afraid of who you are” and Rey’s talk with Luke. I’m still not sure if Leia’s line tips too much towards ‘She’s a Palpatine’ or if it’s vague enough to work, and the scene with Luke will have to be cut down drastically of course but I wonder what the effect will be with the remaining lines.