Just some thoughts on this.
I’m going to echo most of RogueLeader’s opinion, particularly the comments about:
I think you could have a hard cut transition from the Poe interrogation scene to BB-8 outside Rey’s house. Then go into the AT-AT, to the various interior shots and hear echoes of Plutt that she’s imagining, but possibly also some alien jibberish like you suggested, like Teedo, maybe the junk cleaning alien, etc., but you can overlap them to the point that they’re really overwhelming to Rey and us, and then a hard black. Relief. After a beat, fade back onto a peaceful shot of the island.
Additionally, though, my biggest concern with this scene is that it is too on-the-nose. I’m afraid that it gives away too much about Rey’s character too early in the film. The great part about the daydream (“Reydream”) sequence was that it was so short and sweet. But the problem I feel about this version of her dream is that it’s too long and reveals too much too early.
Part of what makes TFA so great is that we don’t confirm that Rey is the successor to the Jedi until the very end of the film. There are hints, like the lightsaber flashback (“Forceback”), but nothing so direct about what her destiny is until the moment the lightsaber flies into her hands during the battle with Kylo Ren.
I’m all for the sequence, I just think it needs to be shorter, more dream-like / mysterious, and less obvious about what it means. I would also recommend not using “The Jedi Steps,” mainly because I feel like that is a theme that is reserved for Luke when this is a sequence less about him and more about the Force awakening in Rey.
Music wise, I’m not sure. Maybe you could play with something like the intro music to The Force Awakens trailer, which was composed by Williams. Or maybe the original teaser trailer music: https://www.youtube.com/watch?v=dhtOwVvQjIc