LOL Jake annoyed the pants off me, I really like Jar Jar more,I think its safe to assume there are a lot more better actors his age doing the circuit, or have done in the past.
The theory about his over confidence to turn him to the dark side sounds about right though, i can see that, but when seeing the film for the first time, i also thought that maybe something happens to his mother that actually causes the turn, something family related anyway. Because at the end of the day it was his own son that finally turned him back to being a good guy again?
As for Jake being cast as a luke skywalker look alike i don't know why that could possible be taken into account, as both luke and leia were twins she was of dark hair like her mother, but that could still meant that luke could have been dark and leia blonde, or both blonde, in jedi don't you notice how dark Luke's hair looks?
Anyway i don't want to get into that lol