I disagree with 2 of your non-evil villains.
I think that Orochimaru was pure evil (even though I love him). His parents died yes and he missed them, but from what we saw of him I don't think that's what drove him to be a villain. Usually these villains are holding a grudge that we see in some shape or form, but I think with Oro he was just evil. Kishi just showed us that as a kid he used to be cute....I mean who wasn't? (Actually there are some ugly babies...)
I also disagree with Hidan. I don't believe Hidan acted as he did just because of his religion. I believe he used to religion to justify his homicidal tendencies. Kind of like when some ppl use a sacred text to justify something they think is wrong because they need to have a scapegoat that doesnt make them the bad guy lol.
Also I believe Sasori to be just evilness. He also lost someone (who hasnt?), but I mean really look at him and his emotional behavior as a child. He was a little sociopath before his parents even died.
I think Kabuto is like Hidan, just grasping at straws to try to justify himself. He better kill all those orphans cos right now we see that he was loved immediately and he feels attachment. He still wears the glasses...I mean at least with Oro he didn't play games about why he was evil, he just owned it. Own it Kabuto!!!