I don't think I buy what you're saying 100%
teya, not because I'm an awkward git (which is true), but because I think you're not being entirely fair to Seven of Nine (and before anyone asks no, I'm not a mindless Jeri Ryan fan who watched Voyager for the T&A after she joined)...
Why do I say this? For 2 reasons...
1) "Crimes against humanity" - I don't think your pinning these onto Seven because she was a former member of the collective would stand up. She was assimilated against her will (because she was 6... it's hard enough to do something about it when you're 26 or 36 etc), and she acted, from that moment on, as a vessel for the collective's wishes. Watch
Best of Both Worlds and listen to Picard explain how utterly destroying it was to have been Locutus and not be able to act under your own impulses and that should lend some weight. The point is, she is now free, and while she
is technically a "human" character (irrelevant of species

) she is missing her "humanity" and needs to explore it. What you're saying is actually a more extreme argument than "as a citizen of the United Kingdom I am responsible for the actions my government took in Iraq." I
have free will, which Seven didn't, and while I can object to what they're doing, in that particular case I had
no control over it, as we saw by the fact the thousands of protesters against the war did not manage to prevent or revoke our involvement. Therefore when the list of regrettable things that happens over there is compiled I am saddened, but I don't feel culpable as an individual, and if that applies to me then I don't see why it can't be applied to her.
Which leads on to...
2) I sort of follow your logic on the "sacrifice to regain humanity" notion, but I see it as a little flawed. I don't think she has to die to atone for her sins, or those of the collective. She's Seven of Nine, not Jesus. She can save lives without having to die, and did on Voyager. If that doesn't make her human, or at least contribute majorly, then what does? How about her relationship with Chakotay and the ability to experience love? Or her friendship with the Doctor? Or her intellectual repartee with Tuvok?
I really think you've misjudged her!
[[Also... if we're now on TheGodBen 6 does this mean he's going to develop some kind of distrust for everything TheGodBen 1-5 believed in and switch sides?]]