Getting creative here, but I'm guessing that annapcoug thought that land under the driveway belonged to the neighbor anyway. So, buy the house, deed over exactly where the driveway lies, and then there's no more issue about him being on the property?

There's definitely merit, either way, to asking the seller to take care of it, whether it's through that means or a formal, written agreement.

As for the termites, sounds like you just need someone to spray wherever there's evidence - probably doesn't need a tent. Shouldn't cost much at all.