My first point is, I was ecstatic in the movie that Anakin was renamed Vader before he adopted the suit. That's the way I'd always read it, and I'd always imagined the homicidal adventures that the original Vader had in his early days. But a lot of the fans found Vader to be so synonomous with the suit that I figured George would end up retconning it and not naming him Vader until the suit was on. The advertising did this, though, with lines like, "Anakin vs. Obi-Wan." Pfft. Screw that. So that was probably my favorite part of the whole movie when Palpatine named him Darth Vader, simply because that was the one thing I really expected them to screw up. Of course, they ended up screwing up so many other things that I hadn't expected...
The only other problem I had was that I thought, in the movie, Vader never really came to that point where he embraced the Dark Side and truly became, well, for lack of a better term, evil. And I agree that the logic in the movie about Vader still serving Palpatine at the end was implausible. In my dream version, when Vader reawakened in the suit, he wouldn't give a crap about Padme. He's moved on. There's the tragedy. If you're going to keep the motive that he did all this for love (which I still find a bit dubious), have the irony be that, at the end, he hates her. He feels, like he did on Mustafar, that she betrayed him. Betrayed him for Obi-Wan, betrayed the Republic, whatever. So, once he comes to that, the only thing he has is his power, which he embraces. The Dark Side is his love, as corny as that sounds. He shouldn't still be whining about Padme. That was one of my hugest cringe moments was the first thing he asks when he wakes up is if she's safe. Be a badass! If he wasn't before (since this hypothesis is keeping in line with the official version and/or yours as much as possible deviating only where I feel necessary... if it were truly my own vision, it would simply be the greed and lust for power (like Obi-Wan claims, but I wasn't convinced) that caused him to abandon what he previously held dear), he should now be a loyal servant. And in that case, there's one deleted scene that would work well in this version: the one where the future leaders of the Rebellion meet with Palpatine, and when they leave, Palpatine subtly suggests to Anakin that he can't trust Padme. And now he should fully have convinced Vader that Padme betrayed him, not that he killed her.
Phew. Okay, that was fun. Thanks for starting me up.