first, trust your gut. if it doesn't seem right, it probably isn't.
finding out those addresses are genuine means nothing. all it proves is that there is a house at that address, which would seem obvious since they would have to have a legit address in order to receive the CC in the mail. the card still could be stolen or the account opened using stolen identity info.
even if you take the money out of your paypal before shipping you could still lose. since it's linked to your CC, if the payment is canceled they will just charge it to your card.
what is the buyers history like? if either the buyer or the paypal account are very new, or have a lot of new activity be worried.
in the future, when listing an item put in the details "shipping address must match billing address", it's not a 100% safety net, but at least your shipment and the bogus accounts can be traced to the same spot.