I vote Esai Morales for Poe.
Laurence Fishburne for Finn.
Tom Cruise as Kylo (seriously just cut and paste him from ‘Legend’)
Sean Young as Rey in Force Awakens, but the rest of the cast and crew feel she is too “intense” and makes them feel uncomfortable, so they recast her with Jamie Gertz afterwards.
I can honestly see them just putting Hammil, Fisher, and Ford in old age makeup