The line?

So I was working on a story for my portfolio game and it came to me that, since it is primarily a psychological game, I wanted to really give the PC a strange past. I wanted him to be sympathetic and yet not a saint. He needed to have something dark, something that would make his divorce understandable and still not make him out to be a victim in everything. My fiancee was helping me come up with ideas for things that he could've done in his past and we started thinking, well what's too dark for a game? What is the line that's going to make people put the controller down and say, no, that's too far, I'm done?
So I want to ask, which, if any, of the following do you think is too dark for a game of a mature type to delve into. I say mature because it's intended for adults and really doesn't belong in the hands of kids, not because it will be graphically explicit.
1) Murder, especially the mindset behind it
2) Rape in any form
3) Molestation of children
4) Torture
5) Psychological torture or manipulation
6) Violent occult
7) Religious beliefs in a dark way (ie - the antipope or something like that)
8) alcoholism and substance abuse
9) spousal abuse
10) adultery
11) brutality towards animals (I mean really, REALLY bad stuff which I won't describe here)
12) abortion, miscarriage, etc...

Also, if you have anything that you'd like to add as something that's too far or you think seems too far, but might be a good idea to delve into, then please feel free to comment on that.

This all came out of a very serious question. I believe that video games are an art form, a storytelling medium which should not be censored, but I also realize that there is the point of audience to remember. Just like in a movie, if you show a person who rapes, tortures, and finally murders a child your audience will want him strung up, hung, drawn and quartered, and shot six times with rusty bullets before you're done. People are not forgiving and playing with these things in a game can alienate your fan base. I'm wary of including a great number of things listed above in my game despite it being a firm placement in the psychological horror genre which has allowed such games as Silent Hill already. I suppose I'm just being timid here, but I really feel this is an issue which should be considered. As I said, censorship is wrong and any storytelling medium should be able to deal with all aspects of real life no matter how dark or horrible they are, but as a form of entertainment, what is too far? It's a difficult question and is very much a person to person basis, but I'd like to get a consensus from the good and loyal interwebs. Thank you for participating in our survey.