I don't think renters put themselves at much risk. I have not ever rented, but it seems like if I did and had a renter fail to pay or issue a bad check, I could simply cancel their reservation and get my points back. If I'd passed a banking deadline, I might be inconvenienced, but renting to an unknown person seems far less risky than renting from a person with a low post count/unknown profile.
OTOH, there is nothing, other than honesty, to keep a renter from taking money and even sending the confirmation letter, and then cancelling the reservation - or "selling" multiple fake reservations to a number of people.
As a DVC owner and Disboard member, it seems like it would be SO easy to defraud people - especially with demand for rental points hitting such highs. That's why I would not rent from a person with a low post count - although I would rent TO a person with low posts.
Rentees are the ones at risk, because all the power lies in the renters hands. Rentees can't call CRO for a refund or date switch, they might have no reciept to prove payment (unless they work with a renter who uses a contract), they can't even call MS to confirm that a reservation was actually made. Luckily, if they follow the guidelines Doc posted, all should go well.