Frankly, they should’ve both just let Hamill and Ford et al. decide their characters’ fates.
Well, yes and no.
Yes, if you’re going for unchanging characters since the actors have inhabited these roles for years and know a whole lot about what makes these characters tick.
No, if you’re going for a continuation of a character arc like Hermit Luke. In this case it’s important for the writers to know what they’re doing.
Not at all. Harrison Ford, for example, wanted Han to die.
And Hamill wanted Luke to go bad in ROTJ. People are just making stuff up now, Lucas never listened to his actors (nor was he under any obligation to).