I only saw Zach being gay because I had read about it, but I think if he'd been around longer it would've been made clear (I didn't identify with him either, and I'm obsessed with my own queerness right now.) I think the point of him was sort of that gay people just exist, quite quietly sometimes, and gradually he'd become more open about it and that would be developed in the background. As it is, with the actor quitting, we never got more than hints, but I find it hopeful that the way the show was going about it -- not him being flamboyant, but not him being totally repressed either (he threatened to "anally probe" Lyle, for goodness' sake.) We'll have to wait and see about what happens in season 2, but I'm optimistic.