So as far as 9 went, I liked it better than 8.
8 was frustrating to watch due to the jumps in character logic, though I did like Luke's interactions with Rey.
9 had jumps in plot logic, but it was more fun in a 'turn off your brain' manner.
But overall, yeah, this trilogy was a mess. Plot points aside, Rey, Finn, and Poe had so much potential to be a cool trio, like Harry Potter and his friends, but 8 just split them up so much they didn't have time to develop a convincing bond that leads into their dynamic in 9.
As for actual plot points, I really wish they went in a more gray area with Rey, having her between Sith and Jedi. She does let her emotions guide her use of the force, which is a very Sith thing, but ultimately she does care for others and the greater good as well. Rey could have had a character arc where she is trying to find a place where she belongs, and then finds her family with her resistance friends, as well as with Kylo.
Finn could have had a character arc where he leaves his strict, regimented storm trooper life to find a richer world and either forms connections with other defectors (like with Janna as suggested in 9) and/or uses his old first order knowledge to play a bigger part in helping the resistance.
Poe's arc could have been him accepting greater responsibility, ascending to a higher leadership role under Leia's wing. It was sort of there in 8 but it was just … ugh to watch.
Hux was useless. Phasma could have been edited into his role.
The Emperor was neat, if only he was established from the beginning of this trilogy.