As a gay person, I feel that LGBT teachers should be nonchalant about this part of our identities. As in, just like you've said -- they shouldn't make a big show of sharing their Queer identity with students. However, we shouldn't be fostering a climate where teachers are intimidated into silence about their identities.

If a student innocently asks a male teacher a (nonintrusive) question about his wife, and he politely corrects his student by saying "My HUSBAND"...where is the harm in that?

That's much different than, for example, a teacher sharing intimate details of their sex lives with students. Or, as you've cited, teachers who take it upon themselves to try to diagnose a student's sexual orientation or gender identity.

The key here should be BALANCE. This is why so many of us have a problem with the "Don't Say Gay" bill. Although its text COULD BE interpreted in mild and relatively-harmless ways...it could also be abused by paleoconservative and theocratic parents or administrators. The slippery slope is what should alarm all of us (queer and heterosexual people alike) about legislation such as this.