I don't think that these folks should be "issued" guns, or anything, but I think a teacher, with the proper license, should be permitted to carry if they choose.
Absolutely.
I'm no longer a teacher. I've spent about a third of my working life as a public school classroom teacher and I am planning on going back within a few years. I have a NC CHP. I would welcome the idea of carrying concealed. I would even use a thumb break, though I don't like them, if that was a requirement as one additional protection from someone attempting to take my handgun. Of course, I doubt I'll get the option to carry.