Again, it depends on where you find the center of the movie, and to me, the center is the experience of living in the city. What is central to city life, is dealing with strangers, which opens you up so much more to randomness and lack of control. In horror movies, hell is other people and in love stories, heaven is other people, and in living in the city, it's both. And he will go anywhere he needs to, to get control back, but he's constantly projected upon. If you're gay or a strong woman or anything that doesn't fit traditional ideals, it has greater weight there.
Violence is in greater relief there because the myth is so much stronger.
No matter how extreme your experience, it's still part of a flow of experience, and so the disruption is easier to take in a city, where there's so much more to experience. For Charlie, it's still impossible to put in perspective, but in a city, I think you're supposed to. Most people see bisexuality as fear of being gay. I don't think the movie sees them that way. I think there are a lot of men who haven't had that dialogue with themselves, who are so starved for intimacy with other men, that it hasn't even gotten as far as whether they want to have sex with them.