I would say that Faith is a victim, but then again, I'd say that about most people/characters (damn me and my thoughts). I think that she had every "reason" to act the way she did. Not excuses but reasons. I understand why she did all the things she did, althought she did of course do lots of stuff that wasn't "right". Like Comma said.. that question.. No, I don't think her rough life cancels the bad things she did, at all, it only makes it understandable. It's never "OK" to do the things she did, but that doesn't mean she's not a victim. I don't think she "deserved" punishmenst either.. I'm not much for punishment in general, I don't think it solves problems, and I don't think that's what Faith needs. She can get better (obviously), people can get better and punishment is rarely the way to "make them better".
As I see it, like Jill said, Faith chose to do the things she did and act the way she acted. But the reason she chose those things, weren't her fault, that she couldn't choose, the way she was, in the beginning, or how she turned out, and so on.. The real reasons..