Never use Western Union to send money to someone you do not personally know. Ever.
Never rent from someone you don't know who "has to have all the money before making the reservation" when you are asking for a reservation well in advance (4-11months or so). Personally I have never even paid a deposit to a pointowner, I always have paid-in-full upon receipt of the original
DVC reservation confirmation letter. Nothing before that, however, because the pointowner is generally risking nothing but a little time if a rentee flakes out so far in advance.
Cancellation/refund-or-not agreement should be spelled out. In my deals we have just agreed on these points by email for my small rental amounts, but for high$ rentals I would say printed and signed/notarized is best.
I think the best methods to pay for rented points to protect buyer and seller are :
Certified cashier's check from a phone-able major US bank with multiple locations...
Personal check from phone-able major US bank with multiple locations...
Possibly US Postal Money order (I have not researched how well the Post Office checks IDs when someone cashes these, however, and there is a dollar limit on each one)....
When I have rented some points, I paid by personal check once and business check once. My business is easily verifiable online as real, and the pointowner had no real risk, since if the check didn't clear he could cancel the reservation. After the DVC confirmation is in hand and after the payment clears, there is very little risk left (usually none for the seller), and a great stay is probably going to happen
Both times I have rented have been from folks with less than 100 posts at the time (the last had less than 10), so # of posts isn't a deal-killer, it's just a small part of the trust picture. The person with less than 10 posts had been a DIS member for almost 3 years, and none of the threads they posted in (all DVC) had people asking them "hey, what happened to my reservation," and the name/address/phone info they sent to me was verifiable both by searching online and through other methods (UPS database, etc.), and payment was to be made only to that person at that address. Plus it didn't hurt that I was renting less than $600 worth of points both times (gotta love the low weekday pointcost at OKW

). So # of posts is not as important as the information the pointowner gives you after first contact. Of course, if someone has as many posts over as long a period as someone like robinb, it's a pretty good bet that they are probably safe to rent from
Here is a recent thread with more tips (but they and the above are just tips--your mileage may vary).
http://www.disboards.com/showthread.php?t=1255828
As for this thread... being the natural born cynic that I am, I personally was hearing alarm bells from the getgo from the details in the original post. But maybe I'm just jaded. Fingers crossed for those who've been seemingly defrauded.