Nev, those are some good points. I especially like how you highlight Luke’s idealism as somewhat of both a flaw and a strength.
I think merely them having more altruistic qualities is something both Luke and Rey have in common. They both do want to help people. Rey wants to help BB-8 and the Resistance. Luke wants to help Obi-Wan and the Princess.
And like you said, Rey’s major characterization revolves around her own sense of belonging and identity.
Personally, I think having Rey join Kylo would have been a really big mistake. I don’t think it was a coincidence that this was the same scene that made Rey come face-to-face with her origins and what they mean for her sense of self-worth. Yes, Rey is looking for belonging, but really in that scene she was presented with a choice between belonging with Kylo or belonging with the Resistance.
I think in her mind, she realized that if Kylo is still willing to kill others when he doesn’t have to, then he hasn’t really changed, but he is just more of the same.
And you have to remember that Rey doesn’t know Finn is aboard the Supremacy, and although she has come to understand Ben more during the film, her one main friend is Finn, and for all she knows he is on those transports. Her letting Kylo keep destroying the rest of the transports would have been out-of-character for Rey.
I think I saw this suggested somewhere, but I can really only picture the moving going two other ways:
One, Holdo could have rammed the Supremacy as Rey was reaching out for his hand, as if she was going to join him, but the following explosion snapped her out of it and made her flee. You probably re-edit this and people could just assume the saber somehow got messed up in the explosion.
Two, Rey could have told Kylo that she would join him if he stopped firing on the transports. He could have said fine, but we are still capturing them. They go down to Crait, Rey would be standing alongside Kylo, seeing him slowly lose his cool. And when Luke shows up, they both go out to meet him, and Luke apologizes to both Rey and Kylo, and he convinces Rey to go run back to the Resistance and help them escape, while he has his confrontation with Kylo Ren.
But, even though I might write up these alternatives, I don’t necessarily agree with them. I still think Rey’s decision to not join Kylo was belonging-driven, but in that moment she realized that Finn and the Resistance could be her belonging rather than Kylo. But I think that choice comes from a healthy place, like, Rey at that moment realized that it didn’t matter if she was nothing, that she could create her own identity, and in that moment she chose that is not what she wanted to be.
I can’t express it really well, but I thought another intentional touch on that scene was for Kylo to keep the glove on his hand, rather than when he took his glove off when he and Rey touched hands earlier in the film. In that moment, I think Kylo was showing something very personal and honest of himself to Rey. But in the Throne Room, it wasn’t the same thing. If he wasn’t intentionally doing it, Kylo is trying to manipulate Rey’s own self-doubt, and I think Rey catches on to this.