I'd change the epilogue so that Ira doesn't tell Luxu he looks different until after seeing his face. That's just a nitpick though.
I would have liked to see a different end for Vanitas. The story lately has shown more often that darkness is not necessarily bad, but Vanitas (despite being a victim of Xehanort himself) still dies as an Unapologetically Evil Dark Edgelord of Evil Dark Darkness. All of the other villains had some kind of resolution to their character, with the exception of him and Young Xehanort... I'm still not entirely convinced we've seen the last of them, though.
I disagree on the Vanitas thing, let a villain just be a villain. Too many people got redeemed in this game a being made of pure darkness to be redeemed as well. Everyone else was pretty much a victim of circumstance, but Vanitas was made of darkness for the purpose of destroying Ventus and possibly has some ties to UX since Ven is from there.
Look at the final 13:
Xehanort - Is the big bad guy
Xemnas - is a nobody made from the big bad guy controlling someone else's body
Ansem SoD - is a heartless made from the big bad guy controlling someone else's body
Young Xehanort - Is the big bad guy's younger self displaced from time
Terra-Xehanort - Is the big bad guy controlling someone else's body
Now take into account that Terra-Xehanort, Xemnas, and Ansem are all a part of Terra as well, fixing Terra and the fact that they carry his emotions was a give in. Ansem was fond of Riku because he was chasing him but ultimately he realized Riku was the better (see Sasuke and Orochimaru) and Xemnas was more amused than anything.
Saix - said that he wasn't really entirely controlled and had ulterior motives from the beginning.
Xion - she showed up last minute and her entire self is one big anomaly but her friendship with Lea and Roxas was bound to save her once we knew she was there.
These two had deep ties to lights we knew about so they were definitely on the redeemed/saved checklist from the get go.
Marluxia - a nobody from the X era who was searching desperately for any signs of his lost sister
Larxene - a nobody from the X era who was along with Marluxia for the ride
Luxord - a nobody from the X era who, at this time, still has a mysterious past and his motivations are unclear
So we have the X era baddies, two of which have a very clear driving force and because this was clarified before KH3 release, it makes sense that they have some kind of redemption for their villainy. So lastly we come to...
Xigbar - He gets no redemption because he is actually Luxu and is being set up as a part of the new villains for future KH games. He blindly follows MoM's orders and we can tell from Back Cover that MoM isn't exactly a good person.
Repliku - He doesn't get any redemption, no matter which version of Riku it was, the one inside of current Riku pulled the evil version out to leave the empty body behind for Namine. That evil Riku was still evil to the end.
Vanitas - His motivation for being evil comes from his darkness and his hatred for Vanitas. Possibly related to X era so he could return.
That leaves us with only 4 bad guys (versions of Xehanort not included) that don't have some kind of happy ending and that's fewer than I expected to end up with. So we should stop trying to redeem him, just because everyone wants to assume he's some kind of misunderstood cinnamon roll that needs to be protected when in reality he would tie your shoe strings together and break a bottle right in front of where you're going to land so he can laugh at your misfortune.