1. The first thing I was shown was a new planet called Onderon, which is ruled by a queen who is allied with the Republic. There's a bit of an upheaval going on right now, though, as half of the population feels that the Republic has done nothing for them but send their best and brightest off to die in an intergalactic war. The other half of the people believes that the queen is doing what is best for her people, and that her people should stand by her side.
The producer told me that you'll be able to pick a side and fight for them, play both sides against each other, or simply remain neutral. It's not really known if there are any advantages to any of these options, but that's part of what made the first game so great. You can choose to do whatever you want, and that's obviously the case here, as well. (gamespy.com)
Closest thing I could find on going against the Republic that is out there.
2. Posted in your other topic.
3. Looking good for a 12/07/2004 (Walmart.com) release date but it could still easily be 2005
4. Not much yet