I would give Obito better motivation than Rin (in fact Rin wouldn't exist.
Madara would have been FV
I would have made Sasuke see the errors of his thinking during his fight with Madara, but still fight Naruto because he also sees flaws in Naruto's way.
Sasuke and Naruto would have been equal after meeting Hagoromo.
There are a few other things, but don't have the time right now