I have so many doubts about Takatsuki's crush on Kaneda-sensei... sometimes I get the feeling she just wants to be him, because she wants to be a boy, you know? Like when she was taking her entrance exam, and she looked at three girls that would apply it and in her home she said she really wanted to go to that school, I imagined she had interest in any of the girls she saw.
Takatsuki's sexuality is still pretty much a mistery to me, because she hasn't showed much interest for anyone so far. Except when she dreamed about Nitorin, and in her dream he was a grown up man.