I can find out whats important to them and what they need or want... but with a realtor involved there are a lot of unknowns and lost in communication issues.Ok... so my questions are: How do I propose this to a realtor and have it actually work? 

It is important to understand that only your belongings without a beneficiary go into a trust (most of the time).

@David Flores - sending during the holiday season may cause a few days of delay in the delivery, and the responses may come in later than usual (because people may be traveling and not picking up their mail), but after all is said and done, I can't see it having a huge negative impact.The more important thing is to make sure you're working with the right list (i.e. - data that is current, accurate and targeted appropriately) and sorting it correctly.

"you got to know your market" what are the most important things to look into?

I've found that the first important step is setting a correct rent price.  

@Mindy Jensen  You might want to survey users (offline) on the importance of search and how well BP does.   

Hey Robert,Being up front with your buyers and sellers is very important in this situation.I'm not sure about PA or NJ but in NY we write our contracts so that the buyer of your home and seller of your new home are OK with either having a double closing or closings near each other.

As @Andrew Lawson pointed out, getting permission is pretty important.

So it's important to run the numbers. 

I think the important thing would be to make sure your heat is on and working so any leftover water in the pipes won't freeze.