I see my sexuality as somewhat separate from me being trans, and somewhat interlaced. I'm only into men and can only think of myself as a man whether I'm with another man sexually or doing anything non-sexual no matter who with. For romantic relationships I can only think of myself as a boyfriend/husband/etc.
I was born female but transitioned to male and happy with that so I'm trans. I see my gender as 100% male but my personality as androgynous. I see myself as a man only attracted to other men. That makes me easily latch on to the label gay, in addition to trans.
I can enjoy all sorts of porn except from lesbian porn, so maybe I'm similar to you on that point, OP. When I watch straight porn though, I imagine myself taking the woman's place, but not like I am her. It's just me there instead of her, in my mind. But I thank goodness for the existence of gay ftm porn.
Whenever I've tried to imagine myself as a woman with a woman it makes me very uncomfortable. Trying to imagine myself as a man with a woman also makes me uncomfortable. My conclusion: I'm not into women. I thought I was bi for a long time before I realised I can't see myself with a woman.
For me, I firstly see myself as a man, simply. Then secondly I see myself as a gay man. Then that I'm trans is just an annoying descriptor I have to drag along with me whether I want to or not. I cannot answer your poll because that's an answer only you can find for yourself. And because my own perception is, I think, too different from yours for me to pick either option. But in my mind you're likely both trans and bi.
Perhaps it could help you if you'd ask yourself if you see yourself as either/any gender when you're alone and not in a sexual context. I think the relationship we have with ourselves should come first, and not the relationships we have with other people.