I have a lot of sympathy for Ventress. She has some of the ****tiest luck of any character in the franchise, at least the characters I'm familiar with. As you said, she empathizes more with the Dark Side because her life has been filled with pain and loss--and when that's what someone has known, it is far more difficult for that person to feel empathy or compassion. How can a person feel what he or she has rarely been shown? But whether Ventress should have thought of herself as more than anything but an assassin, it is certainly understandable that she wanted to consolidate more power for herself so that she could have some measure of control of her own life. She had learned that no one would look after her if she didn't look after herself, and more power better enables her to take care of herself. I found Dooku more sympathetic in Dark Rendezvous as well. He remembered his mother, and he was given to the Jedi not for the reasons that Anakin was--to have a better life--but because his mother didn't want him. He was abandoned, and at the end of the book, he finds himself alone again due to his rejection of Yoda's offer (or in his mind, his inability to accept it), walking on a beach.