I like the amount of thought that's gone into it, but right off the bat:
Changing Owen so he's in a better decision to say 'Anakin should've stayed here and not gotten involved...' or whatever.
First of all - he never actually says it, this is just Obi-Wan mouthing off.
Second - this is quite clearly an opinion formed in hindsight. It's been twenty years, and Owen thinks to himself "well I think Anakin should've stayed here (when he was 9) and not gotten involved (by leaving the planet, becoming a Jedi... whatever).
It is simply unecessary to change that aspect of the story, it already works fine. If I were you I'd worry about the bigger holes. Like eh, well... like me! I've been told I'm a 'hole' of some sort on this forum. Bwahhaah.