People on here are actually wide in the slash fan-base it's not my cup of tea (except occasional fem-slash) but it's still easy to identify a good writer from a bad one and thats what most of us comment on even if it wasn't our style.
SO pretty much don't fear :]. But rate the story correctly or that could get you reported.
Nothing and no one but yourself can decide if you are gay or not. Writing those type of stories means that you're open-minded and accepting of other life choices than your own. I wrote a slash once per request, though it wasn't very good. I have no problem with writing or reading same-sex couple stories and I'm straight. For me, it doesn't matter.