If gender never existed, or if sex and gender were never seen as mutually inclusive, would people be attracted to someone's gender identity or physical sex?
That's an interesting question. I'm not really sure what to say. If gender didn't exist, wouldn't everyone just be pansexual? After all, since there would be no genders, we would just love each other for who we are, not what is between our legs.
You mean if everyone had total free will to chose their gender expression? Being bi I doubt it would matter much to me, but I'd be attracted more to their chosen gender than biological sex. It's much more tied to personality in that respect, so deserves more attention.