I think your ideas retain too many current prequel elements - Anakin, Owen and Obi-Wan should NOT live on Tattooine, Anakin should NOT have anything to do with Threepio's "origin," though your ideas are indeed better than those in TPM (I do like your Artoo idea, though), and the whole Lars family thing just feels too clunky. I think Owen is the only member of the Lars family that should be seen in the prequels.

Erikstormtrooper's ideas I like. I don't know about the last name thing, but it's interesting - I just think you're taking the "no longer has any meaning to me" thing a little too literally. And I don't think Luke/Leia's mother should die. In fact, it might be a good idea for her to be an Organa, or at least a member of Alderaan's royal family. And Alderaan should be a major location in the trilogy, NOT TATTOOINE. There's already plenty of time spent on that planet in the OT.