I disagree. Quit claims are far from common in any market for a house sale. They have their use, but THIS is not one of them.
Your purchase contract should have required them to convey the property by clear title, not just a disclaimer that they gave up whatever interest they had. You should have had a lawyer at the time the contract was made.
It cost a REPUTABLE seller NOTHING to give you a general warranty deed. It only costs him if he DOESN'T really have clean title.
Having the seller's attorney prepare the closing accounting isn't unreasonable (generally it's the buyers call, but if you chose to go that way, that's up to you).
I'd still get owner's title insurance. Especially, given the dubious conveyance involved here.

