I think i feel like i can relate to your boyfriend- i dont flirt with guys but i have found that people often wonder if i am straight or gay- i think it is because i do not fall into the stereotypical image of a man- that false image that gives rise to the myths that plague recovery.
For me also i have had many girlfriends and i have never asked them out, i have never intiated any of it, it is always the girl doing the intiation. That is understandable for me i think- intimate situations can seem dangerous, after all it was situations of perhaps a false intimacy that hurt us so much as children.
The submissiveness you talk about may be a learnt or conditioned thing, when we are young and we are having these things that we don't understand being forced on us we see that we have no control over any of it, not even control over our own bodies. Sexual experiences, like i said, can seem very dangerous. Also being in sexual situations can be triggering for a survivor, there are risks of dissociation and flashbacks. The idea of feeling dirty is also something that alot of survivors express.
You should indeed respect your boyfriends wishes and understand that he will deal with this at his own pace, and accept that he may never talk to you in much detail about these things- that is his right.
The comments your boyfriend has made on sexual orientation do not seem at all unusual to me. His friendships with gay men also do not mean that he is gay. The fact that he was abused by a man sexually does not mean he is gay and that will not make him gay- i don't believe that is how it works. Actually, even abusers who are male who abuse boys are often not gay themselves- abuse is about power over a child.
His apparent attraction to men may be a real attraction, but that is something that only he knows, or it may be about confused sexual boundaries or it may be something more complicated, or it may only be your perception- perhaps your perception is altered by the myths that abuse can make somebody gay (it may have a small part to play). Also, even if he was looking at male pornography that similarly does not make him gay, often porn is used as a way to numb out or to connect to ideas or reach out to different things, perhaps to try to understand the things that were done to him, so that it doesn't have to hurt so much inside.
Yes, confusion is common, his behaviour describes things i have heard before.
I believe the best way to help is just by being there to listen when he needs to talk, and allowing him to do things at his own pace, it is important that he has full control over his own recovery process. You could also direct him to this site.