I'm VERY reticent to verbally accept and back out. I think that doing that will very quickly spread a reputation.
It won't. This is something a lot of people in these parts think will happen, but it won't. You're not that important.
Having said that, I agree that it's totally wack for #2 to be talking like this before their interviews are over. There are plenty of examples of people getting lots of positive talk during the interview, and then never hearing from the potentially wonderful employer again. It sounds as if the main reason to take #2 is geographic anyhow, and I don't think that's enough by itself.