Throwing it out there as an interesting discussion starter
"If you where given the Force Awakens plot from JJ, and had free reign, given his plot lines in TFA, where would you have gone with it"
I've typed the above without pondering it myself, so will edit with my views later
I think a key thing that needed to happen is to make Rey likeable. The people who say she was written as a classic Mary Sue are absolutely right. Kylo was trained by Luke, who took down the empire and the two biggest baddest sith lords ever, yeah he didn't kill the emperor but his strength of will to fight the dark side is what led to the emperor trying to kill or turn him and that led to his death.
Anyway the only way I could see trying to fix TFA by making Rey less of a ridiculous elite jedi having never done half a second of training is to make a storyline where her memory was false. She wasn't abandoned as a kid, really she was a jedi, sith or just someone on her own who trained for years in the way of the jedi but for some story line reason either lost her memory or had her memory erased. Like, hey, maybe she was the sole survivor of Kylo's attack on his training facility, she helped him find the original Jedi place then left and had her memory of it erased. So she was a bad ass jedi but didn't know it, so when she found herself in these situations without her knowing it her training had helped her.
TLJ could have started off with Luke welcoming her back, and then her utter confusion. Then a large part of the rebels beating Snoke becomes that Rey actually had the location of a hidden technology or ship they stashed somewhere that could be used on some suicide mission to kill Snoke and the film revolves around her regaining her memories.
I say that in such a way that I felt the biggest flaw of TFA was that a untrained person who had never used or felt the force was suddenly using the force to fly a ship (why she ever flew or knew anything about the Falcon was completely unexplained... she was working out in the desert and the boss guy showed her no love, when would she be working on, learning about or flying those ships?), use force mind tricks on a highly trained sith and beating a highly trained sith in combat with a lightsabre she'd never once used, nor had she used the force to fly a lightsabre to her. It broke the film, she was unkillable, unmatched, and as good as the best trained jedi/sith who ever lived. IF you don't find a way to write around that you end up with a ridiculous boring and unlikeable character.
Regardless of what I came up with had I been in the position to write this film, snails pace chase in which with an entire fleet at their disposal no one jumped ahead of the slow moving object to block it in would not have been something I came up with.