I counted only 4.
Rin, having an inner struggle who she likes more but def. will go for either Sensei or Otoha
Molly, being head over heels into Rin (can't blame her) but this will probs never happen. Sensei will probs be the one "saving" her (before pushing her down the abyss like anyone else)
Otoha, seemingly not being against Rins advances, but I am rather certain this is more because every girl fell for her and she is more like resigning herself to that role than actually feeling comfortable with it
Nodoka, who.... I have no idea. I think she is so desperately to actually live through herself (and not stories of others) that she will probs do quite a lot mistakes despite her intellect. Yes, I specifically mean Sensei as the prime suspect there.
Sana, Chika, Yumi, Futaba, Maya, Makoto, Kirin, Noriko or Miku show no actual signs of being interested in girls (that I am aware of).
Ami and Ayane kissed, twice if you can believe Ayane (and the first kiss seems quite important as Ami has no idea about that and neither has a reason to lie about that so there are high chances that both tell the truth, which is just another puzzle to be solved). But none of them prefer girls over Sensei. ^^
And finally we have Tsuneyo, who thinks she is a lebanese, not a lesbian. ^^