1. Everyone and their mother already knows how gay Hetalia is. Are those seriously the only things you can come up with, anyway? 2. No, they're put in the unknown gender section because they look androgynous and the viewer may be confused on their gender. You can headcanon them as trans if you like but to Himaruya they're male (and just because someone looks/acts feminine doesn't mean they aren't male)
http://rusfra.tumblr.com/post/88216976761/hey-never-forget-that-hetalia-has-canon-queer
2. No, they're put in the unknown gender section because they look androgynous and the viewer may be confused on their gender. You can headcanon them as trans if you like but to Himaruya they're male (and just because someone looks/acts feminine doesn't mean they aren't male)