I've been on the other side of the transaction, but here is some info from my personal experiences.
As the owner of the points, there would seem to be minimal risk on your part. You set the rules. I've rented twice. On one occasion the renter wanted about 1/3 down before making the ressie and the rest within a week of the reservation being made.
The other transaction was only done on about 2 mos notice, so I ended up just sending the entire amount at once (after the reservation was placed).
I know that many people are more lenient in their payment policies--allowing people up until 30 days before their stay to make the final payment. I guess it depends upon your personal preference and any Use Year implications if you should fail to receive the remainder of the payment.
Another area in which there is some risk for you is with regard to damage to the room.
DVC could (emphasize "could") bill you, the DVC member for any damage to the room. I guess the moral here would be if you're talking to someone about renting your points and they say "the room is for our 21 yo son and a dozen friends for Spring Break", you might want to think about backing out of the deal.
You can typically address these issues with a simple written contract. Make sure the renter knows that you risk losing your points if they try to cancel after a certain date, and it is well within your rights to at least assess a penalty if their plans should change.
There are pleanty of people looking to rent points, so don't enter into an agreement if there is doubt on your part.
Other than that, your biggest issue is likely to be the hassle factor. You'll be contacted by people who aren't really serious. Others will want you to check availability on a dozen different date / resort combinations. Count on most people wanting a Standard View room at BWV and not understanding the limited availability. Depending on the number of points you have to rent, you may have to juggle several potential renters. As I understand it, most people are wanting 60 points...80 points for a studio rather than 200 for a 2B.
And most of all, remember that to the potential renters you are a complete stranger. They are as leery (if not more so) about the process than you are. The couple of times I rented points I was on edge until I finally had that room key in my hands. I spoke to the people on the phone...exchanged dozens of emails...and still there was a part of my brain that wondered what the heck I would do if we arrived at the resort and had no room.
If you are hesitant, consider just dealing with existing DVC members looking for a few points. If you "rent" your points to an existing member, you don't need to worry about making their ressies. They pay...you transfer the points (call to MS) and you're done.
Good luck.