One thing GL did right in the prequels, he saved the Vader reveal for the end. It made a much better ending than any of the prequels before it. I think JJ might have copied him a bit when he saved the Luke reveal in Ep 7 for the end too.
Not in my book.
I would have had Anakin missing assumed dead by the beginning of Episode 3 and Vader pretty much as we see him in Episode 4 only helping the Empire hunt down and destroy the Jedi wearing a mask to hide who he is. Something that becomes more necessary when Kenobi makes him go all meltyburnburn.
I would have done this by having Anakin a young adult in Episode 1 with a wife who isn’t a queen that he gets pregnant before running off to be trained as a Jedi by Obi-Ben.
I’d have given Mon Mothma Padme’s role but not Anakin’s bed.
That way when you see her in ROTJ it’s a call back to the heroes of the first episodes.