you are actually renting a reservation and not pts. the DVC owner controls the reservation until you check in - member services will not speak to non-members regarding their reservation so non-members cannot actually do anything at all with the pts themselves.
(but you do pay for the reservation based on the number of pts used...so there's that...)
And to save yourself grief, don't respond to private messages from people you didn't initiate contact with. There are a bunch of unscrupulous people out there who like to prey on the inexperienced.