Thanks for sharing those!
I know some people were hoping to see Luke’s spirit in contact with, or haunting, Kylo in the film, since TLJ sort of hints at it. It’s possible we could have Kylo hear Luke’s voice, maybe, but it would be hard to create a scene where he actually sees him. But, I did have another potential idea for it.
What if we added a hint or two that hints at Luke being responsible for the vision Kylo has of Han? I wouldn’t want it to be super obvious, because I like the ambiguity of whether it is a vision or just in Kylo’s head, but I think it would actually work as a good pay off.
One of the last things Luke says to Kylo is, “Strike me down and I’ll always be with you, just like your father.” And then, his line, “See you around, kid.” Definitely harkens to Han, since he called both Luke and Ben “kid”. So even then Luke knew how much even referring to Han would influence Ben.
When Ben first hears Han say, “Hey, kid”, maybe you could overlay it with Luke saying, “Hey, kid”. Or the line could transition to Luke’s voice to Han’s. And maybe at the end, after Ben’s throws his saber away, when he turns back around, maybe he could hear Luke’s voice say something very quickly, or we could see a very faint glimmer of Luke’s force ghost disappearing just as he turns around. Like I said, I don’t think it necessarily should be super obvious, so you could just run with a few of these ideas, and not all of them perhaps. But I think this would be a good way for Luke to help Ben in his time of need.
Another cool thought about it is that if you did this, Luke would be helping Ben and Rey simultaneously, giving his guidance to both of them. And even though the scene is about Ben forgiving himself, I think if Luke was implied to be behind the apparition, then in a way Ben would be making amends with Luke, Han and Leia through this single conversation.