Thing #1: Use George Lucas’ script instead of throwing it out. I don’t know what was in that script, and hopefully it will surface one day. But only he really truly knows where the story needs to go.
#2: In absence of that script, the backstory for the film is far more interesting than the film itself. The battle of Jakku, the formation of the new jedi order, Luke training Han and Leia’s kid. That kid falling to the dark side etc. It’s an amateur writers mistake to not tell the most interesting part of your story.
I can even picture the opening scene of such a film. The unknown figure of Kylo/Ben being approached by a hooded figure, the lightsabers come out, seemingly the hooded figure is an aggressor, after an intense battle the hood comes off and it’s revealed that it was Luke Skywalker, and Ben has just failed another spar.