You're not going to believe this, since homophobia and gay-hate is probably my #1 Berzerk Button... but I'm not offended by use of the word gay, as in "that is so gay". Yes, I think it's juvenile and stupid, but honestly, it loses a lot of its meaning when used as a swear word. It's similar to calling something "fucking retarded" - yeah, it's not a phrase you should say, and people who are or know developmentally challenged people have every right to be offended... but in terms of "that's so gay" and shit like that, I choose not to take offense because honestly, there's enough actual hate going around for gay people, that you don't need to start going after middle-and-high-school students for the stupid shit they say.
Now, everything else you mentioned, on the other hand, pisses me off a lot more. Nobody in my high school threatened to beat me up, but they made constant accusations regarding my sexuality, which I would vehemently deny, only to inspire more shit from them. I didn't know any other gay males; the only other gay people I knew in high school were a bisexual girl who dated my friend for a while, and a lesbian who I talked about in my F&B thread.
However, that lesbian classmate ended up being a Closet Key for a Mormon girl I knew, and I later learned after they got married that her parents sent her out of state to a Straight Camp, where she was suicidally depressed until she discovered the lesbian classmate I knew loved her; with that, she escaped the Camp and hitchhiked back to our state and got together with her.
I hope that makes a goddamn bit of sense without using names.