Anon, I've been trying to find an answer and I think that you do not have to escrow the homeowners insurance. But...if the loan is in a flood zone, you may have to escrow the flood. I can't get a handle on this part of the issue because of the "voluntary" exclusion- sorry.
Edit: I'm just learning escrow so don't take this as an answer - hopefully someone with a clue will set us both straight.