I do not think the risk is that great as I have seen at least one story of a member losing their membership because of deceptive practices.
I just completed a transfer of 4 pts to another member. For 4 pts, I just did it and asked him to send me compensation afterwards. On a larger transfer, I would expect some form of upfront payment.
It all comes down to trust. If you can't trust a fellow disney lover, who can you trust?