While I agree with the general idea of what you're saying here, your profile picture heavily suggests that your opinion has been compromised lol
I think her dying would be a pretty shitty direction to take the story. It clashes with the overall tone of the game, and while she can be a massive piece of shit at times, she's not so bad that it wouldn't be a tragic outcome.
Especially since it's made clear she was groomed to be this way, by a dad that she clearly loved. Like, the whole "don't trust anyone, and keep anyone you have to trust, keep them at arms length" is a classic isolation tactic to make sure she's easier to control, and it's fucked her up.
I don't really see a way of selling her death as anything more than a surprise downer ending. The only thing I've seen pull it off is season 1&2 of Skins, and that generally has a much less light hearted tone than Being a DIK, and failed at it two out of three times, because it causes a massive tonal shift each time.