90% of the EU was garbage. Bad content in good books, things that don't make sense in the canon (Starkiller) etc. Lucas already grabbed many of the better aspects of the EU in the prequels and clone wars.
No one needed the EU. what we needed was a cohesive story. We didn't get that. But the films aren't why people are the way they are. And the biggest mistake Disney made was letting the Fandom Menace change the direction of the final movie. Trevorrow's script was a continuation of the story. Not a deletion of tons of history. What was wrong about it could have been fixed. Instead we have JJ throwing the baby out with the bathwater. Literally dog****.
Again I wouldn't have done 9 like Treverrow would have done. I would have included a gap adn time jump. Leia is killed in a flashback to start the film because of Carrie's passing. We now have leapt forward say 5 years. Not too long but long enough that the first order can complete their galactic conquest, that the resistance is able to reform and more importantly, Rey is able to start creating her Jedi Order. Not saying she needs a ton but give her a Padawan. Make it the kid from the end of TLJ, make it Finn, who cares. The film opens on the heros in the same way RotJ opens that way. Heroes setting forth the plans they need to do to get back on top. The core crew going to do a mission to get some asset they need to defeat the first order. Lets say in this one there's an rebellion weapon cache that Lando stored away instead of letting decommissioned as he feared a return of empire forces. These weapons are important to reoutfit the resistance. Finn, Rose and Poe lead a resistance force to the capital world be it coruscant or whatever, to organize guerrila warfare against the first order. Kylo Ren after conqueing the Galaxy has become obsessed with power and found a sith holocron intended for Vader in Mustafar (insert scene of him killing Sith cultists protecting the holocron) But anyway he finds a holocron that has Sideous talking about a wellforce of dark side power in the unknown regions and he has located it. First he has to convert Luke Skywalker to replace Darth Vader though. Luke appears next to him as a force ghost and talks about how well that search for power went for Palpatine, dead with everything he cared about destroyed. Kylo swipes at him but passes through him and luke continues to badger him until his point is through. Rey goes on a mission to find out where Kylo is and finds his ship and tails him by putting a tracker on his ship. She follows him to this wellspring of the force, not jsut the darkside butt he lightside as well. As the grandson of Anakin the wellspring speaks to Kylo. The light the dark both. Rey appreaches him and tries to redeem him, he freaks out and attacks her. She defends herself from him until her Padawan comes in and she gets distracted giving Kylo an opening where kills her and goes to the well after easily force pushing the padawan against the wall telling him/her he'll make them his apprentice later (if not finn)
Back to capital the resistance is pitted in heavy guerrila warfare with th efirst order. Hux leading the first orderis successful in dealing with many of the resistance battles and eventually the heroes are captured.
Back to wellspring Kylo staring into the wellspring is joined by Anakin Skywalker. He tells Kylo about how his conquest for the darkside lead him to losing everything and the onlything that pulled him back from losing everything was his son. He realized his attachments weren't what made him weak like what the Jedi and Sith told him, but made him strong. Kylo looks to Rey and back at anakin as a tear forms anakin nods and kylo reaches into the wellspring and heals Rey. Doing the thing that Anakin couldn't do because he was lied to his whole life. Kylo apologizes to rey and throws his lightsaber away. Rey reaches into her back pocket and produces Leia's blue lightsaber giving it to Kylo. Insert flashback if you need it. But cut back to the climax, Kangaroo court of the first order, the heroes of the resistance are on trial. Hux is ready to execute them when in walks Ben Solo, Rey and her padawan (if not finn) Ben SOlo tells everyone that the first order is a sham (mind you this is broadcast on Holonet) and that he is disbanding it leading to hux freaking out and telling him no it's not a sham he's a false leader and orders guards to capture him leading to a prolonged battle where rey frees her friends who join the frey. Ben tells Rey and Co to get to the Falcon and get to his destroyer and gives them a self destruct code. Kylo dies destroying the first order from the inside while his friends fight for everything.
I didn't even try hard and wrote a better story than RoS. And didn't introduce much new canon breaking stuff.