In case of Anakin, and the whole PT the surroundings are unfamiliar and the character does not know who he is. Is he good or bad? Not yet determined. Combined with unfamiliar surroundings, it does not work any more.
The same can be said about Padme. Who is she? Elected queeen - we don't know such people. Senator? Politician who is sick of plotting and politics? Jedi Knights who are generals and leaders of army? It does not add up.
Excellent points.
I got no real sense of who these characters were in the prequels. I didn't care about them at all. Their motivations seemed entirely unclear.
I don't think Hayden Christensen and Natalie Portman are especially good actors. There's a certain one-dimensionality to them both. Maybe it's because they're still young and don't have the chops yet. Whatever the case, it seems to me that they were chosen for the Star Wars movies mainly for their looks.
As for Mark Hamill, although he didn't have much success as a screen actor after Star Wars, he has been successful as a voiceover artist.