So, first off, I'd have ditched the OT reboot. Luke and Leia were successful in restoring the Jedi and the Republic. The sequels would be about them passing the torch to a new generation and building something that can survive without them when they're gone.

Luke would have fixed many of the problems with the prequel Jedi, such as their refusal to allow emotional attachment and only training children. However, this would come with it's own set of problems as those rules existed for a reason and Luke now has to deal with the consequences of getting rid of them.

The villains, rather than being Sith or Sith expies, would be an army of Light-Side zealots from outside the galaxy. Basically the prequel-era Jedi turned up to eleven, they seek to bring peace to the universe through the complete eradication of all potential evil. Their leader, an extremely powerful Force wielder on the level of Yoda and Sidious, felt the destruction of Alderaan 30 years ago and has been planning the conquest of the Star Wars galaxy for its own good ever since.

I would keep the general idea of the OT characters being supporting roles with new characters as the heroes. This could be Rey and co, or it could be original characters.