To your point about about her being fully corrupted was what I meant by having one off "Anna as a pure sex toy used by multiple hands" side adventures that will not advance her current corruption progress by her disassociating from it, by seeing it as something she had to do to save someone not to be repeated and linking it with say her hero complex of focusing on the outcome not the deed. Therefore allowing for some super hot scenes with still innocent Anna now versus later game fully corrupt Anna.
But the problem with that, is that Anna isn't innocent anymore. Just because she acts like she's innocent, doesn't mean that she is. Anna maybe wants people around her to carry on believing that she's still the relatively pure girl, that came to Sun City just over a month ago. But by now she not only knows she's become a slut, she actually enjoys being one. She just doesn't want to admit it yet to other people, because she still feels somewhat ashamed and worries what their reaction will be, if they discover what she's become.
Anna's small town innocence has gone, and she's never going to get it back, whatever path you take in the game. All you can decide is how much more her condition is going to change her, before someone comes up with a cure. Because even if she gets cured, she's not going to go back to the way she was.
Even if you've allowed Anna to have the bare minimum of corruption, she's still going to have been dramatically changed by what's happened to her during the game. She'll still have experienced the ugly side of life in Sun City, been exposed to sexual abuse, blackmail, extreme criminal violence, murder, drugs, prostitution, porn and being thrown in jail. How can you imagine that someone who had to face up to all that, could still be innocent? And that's just the version of Anna, who hasn't been allowed to fuck around with multiple characters, and start to thoroughly enjoy it. That version of Anna is miles away from being innocent by any reasonable definition.
So this idea, that Anna can carry on being innocent, because some people enjoy the idea of her being fucked against her will. Just simply doesn't make any sense anymore. Once a person has been corrupted enough, they're not going to view that kind of sex the same way anymore. And Anna is now past that point. As I said before, that is the nature of corruption. Eventually the person being corrupted accepts as normal, things that in the past would have horrified them. And once that happens, their innocence is lost forever. And all they can do after that, is to pretend.