I don't think the attic vents should be sucking anything in, they should be letting hot air out, via thermal convection. Of course, this isn't to say that embers couldn't be blown in by wind.

Another thing to remember is to keep your fire hydrants visible. Keep the weeds and shrubbery away from the hydrant so their location is obvious. Many places have a blue reflector embedded in the middle of the street to mark the fire hydrants, but some don't.

If you're downwind of a fire, it's pretty hot as it approaches. It will probably dry out very quickly any moisture you apply to your roof. But if everyone does it, you're probably lowering the water pressure for the fire department. Suit yourself. Keep your fire policy number with you.

You can't stop a wildfire, and you're crazy if you think you can. Get out while you can!

Sue