I've been thinking about TLJ/IX lately and cranked this wishful thinking scenario out. Flame on!
Just things I'd like to see.
A time jump of 2-3 years that features a montage (highly unlikely of course) of the new Rebellion growing - Leia voiceovers, maybe even Leia CGIed from a distance giving speeches, recruiting planets (like Mon Cal). Poe is with her and we see him transition into the new voice of the Rebellion. Similarly, Finn is trying to rally disenfranchised First Order members or is trying to seed a resistance inside the First Order - hopefully with better results than his bumbling aboard Snoke's ship like a kid in a FO Halloween costume. We also see Rey finding and recruiting Force Sensitives, hopefully not including Oliver Twist kid from TLJ.
Catching up to the present, the movie opens with Leia's funeral - she's exhausted from another recruitment push and never recovers from her efforts to save her own life in TLJ. Poe is now General Dameron, Finn has a real title in this military, and we've got the look of an actual army - not 3 capital ships and the Falcon. Hell, make Chewie an officer as well, lord knows he's done enough. And the first twist is that the Rebellion and Rey's new Jedi are not separate; these Jedi are part of the Rebellion, and Rey is their leader. And the first time we see her complaining or frustrating about her students or her own ability to teach, instead of talking to Poe, she's talking to the Force Ghost of Luke.
Hopefully, this leads to our first-ever Multi-dark side vs. Multi-light side fight; an upgrade of Ren/Rey vs. the Praetorian guards, which was really awesome, but would be trumped by Knights of Ren/Kylo vs. Knights of Rey/Rey.
Luke said in TLJ that he couldn't save Kylo, but that doesn't mean that Kylo can't save himself or perhaps be redeemed by Rey or (long shot) a Force Ghost of his mother.. The best plot I can imagine would be a rupture between Hux and Ren that has Hux willing to do basically anything to win the war, and Kylo finding enough of his own humanity to do something about it at the end. Not exactly the same as Vader killing Palpy to save Luke, maybe something closer to Rukh assassinating Thrawn at the end of "The Last Command".
