About the C3PO and Padme's plot hole, those could easily be avoided, had GL had put some thought before writing the prequels. Was it REALLY necessary to have Anakin creating C3PO?! Was it really necessary for C3PO to be on the prequels?! Why do everything GL does is for toy selling? I mean, he had C3PO in 3 different forms, just so he could sell 3 different toys, how stupid is that? And suddenly he faced himself with a HUGE plot hole, Owen Lars OWING C3PO, because I belive he didn't even remember what happened on episode 4. So his solution to it was simply to ignore the plot hole and hope that the fans come up with an answer for it. I'm am absolutely sure that GL thought that we would eventually discuss it and come up with a solution to all those plot holes. How wrong was him.

Now, about the whole exile: I also thought it could be a plot hole, a reason for Obi Wan hiding in Tatooine on ANH and Yoda hiding in Dagobah in ESB. But perhaps they had a reason for it, and all planned out for what Luke would eventually do. Or... maybe it IS a plot hole and GL was just waiting for someone like me to come up with the answer...