I loved the movie, just loved it. One thing I might change is the dialogue between the director and Vader on Mustafar. I would simply cut vader’s line about chocking on one’s ambitions, (he’s a sith for Chrissakes! Ambition is all he knows.)
I hated that line because Darth Vader does not use one-liners. But I don’t understand your point about him being a Sith.
And I hate the idea of putting anything more from ROTS in.
“I find your lack of faith disturbing.”
As I previously corrected myself, he does not use cheesy one-liners.
Anakin does, though. Now that can either be a good thing or a bad thing depending on how you want the prequels to fit into the universe. There’s plenty of people that want to ignore the prequels and treat the two trilogies as separate, so anything that makes Vader more like Anakin might be annoying or even sacrilegious.