So my Republic characters pretty much have their stories/background thought out, but I'm having a bit of a problem with my Empire side characters. I generally tend to gravitate towards the "good guys" so trying out sith/empire characters is very foreign to me. I have 2 characters that I would like opinions/suggestions on.

Female Twi'lek Sith Inquisitior (Sorceress)- So this character is kinda mixed feelings like myself. Her race is regarded as nothing more then "slaves" but her acceptance into the Sith ranks has given her a little respect. She isn't evil for evil sake, and in fact is somewhat "compassionate". She remembers how it was to be a slave of the Empire and has not forgotten (or forgiven) what that felt like. To that same token she does not want to appear "weak" in-front of her peers so she walks a very thin line. She serves the Empire but loyally would be a lose term for her. She believes changes should be made to the Empire and does not agree with the treatment of its citizens. She has no love..or hate for the Republic, simply seeing them as another force in the galaxy.

Male Pure Blood Sith Warrior (Marauder)- Again not looking for an evil just to be evil kinda character. I see this Warrior as a "honorable" one that only kills those worthy (by his standards) to die by his lightsaber. He definitely believes in the empire and serves it loyally. He does not "hate" the Republic, he sees them as the ultimate challenge, having nothing personal invested in the struggle.

Anyways thoughts ideas suggestions?

If you keep in mind that both sides regard themselves as the 'good' guys, you should be half way there.

The Empire is about enforcing law and order (at the expense of civil liberties and freedom), you don't necessarily have to be evil to do so. Your character should just have the firm belief that the average citizen is just too dim to take care of him/herself and to know what is good for them.

Take an example from RL history, thousands wouldn't have supported a Soviet regime (just as an example) if they didn't believe that it was an improvement on the Imperial reign pre 1917. I am sure that millions of people living then were good decent people and joined the military, police etc for altruistic reasons and not just to take advantage of corruption, bullying etc.