1. If you thought his switch to the dark side was sudden, then watch tpm and AotC again and this time pay attention.
"The boy is dangerous, they all sense it why can't you?" and "I sense much fear in you. " "Fear is the path to the dark side"
from TPM; establishing that he was already on his way to the dark side as jake loyd.
In AotC, he slaughters women and children, also offscreen. He gives in to the dark side when his mother dies, he just doesn't tell the other Jedi. "I'm going to become the most powerful Jedi ever"- so by the time we get to rots he has already killed innocent kids and decided that he wants power more than anything, so the killing of younglings in rots is nothing new. He didn't turn to the dark side for Padme, he did it for his mother.
2. As for the political aspects of the new trilogy, the giving up of democracy/representative government for a dictatorship is a recurring theme in history, and has happened countless times too numerous to list. The most famous right now would probably be the roman empire and germany ceding power to hitler, with the US recently beginning a journey in that direction, only it seems as if it may be corporations that are seizing control rather than any one power hungry individual or political party. This was predicted long ago in Alien, that Weyland-Yutani would control everything. As for which corporations will end up owning everything in reality, "difficult to say; always in motion is the future." Are there even any truly democratic governments left in the modern world?
3. The dialogue might not have been brilliant but a lot of it was realistic, and I thought Anakin's foot in mouth moment where they're arguing about who loves who more made the characters and relationships more believable (though not less sappy).
SPOILERS
4. I thought it was awesome when JAR JAR was revealed as the identity of Darth Sideus, and Anakin's father. All that misdirection to make people think palpatine was a Sith, when really it was Binks all along. So all the people wishing they could see binks die had already gotten their wish in rotj.