Nice to meet you, Jack.
I think I've got a sort of similar experience? Apparently to people in my school, I was in the group that was just assumed to be lesbians. And also I was called one of the manliest people in school, next to my friend Haunani.
Not that I mind. Just because I don't dress like a girl with all your frilly blouses.
I just shake it off though. I don't think I've had anyone just come out and ask me if I was gay or not.
I'm glad that your mum isn't like those that pretty much condemn their children for being gay (which I'm going to assume my mum is going to be like). Just take your time, you'll eventually discover your orientation. And come out when you feel comfortable about it; I won't lie, there will be people that probably won't agree, but bollocks to them, huh? If they can't like and accept you as you are, then they're not worth the time.
To address your question, I'd say I'm about 75% out of the closet. Most friends/classmates already know, I've marched in the Honolulu Gay Parade, and I'm proud of who I am. However, to my family, I'm just a straight girl that dresses like a boy. Sometimes I wonder if they've gotten any of the hints, but oh well.
And for gay adoption, I do believe that it should be allowed. Mainly, I admit, because I want the option open should I want to adopt a child rather than have my own. I don't see the problem with a gay couple adopting a child; just because a child has two mummies or daddies doesn't mean that those parents are unfit to take care of the child or that the kid will be void of learning things they would from a parent of a different sex. There are other outlets that a child could learn those certain things, or could very well be taught by the parent they have now. A child with two gay parents surely has to be better than not having parents at all, right?
*will shut up now*