I included a link below to your state's association with all the requirement info.Keep in mind that getting into Real Estate is not a cheap adventure. 

Quote from @Luis Herna: Let say I am a licensed real estate agent in oklahoma and there is one buyer in new York wanting to buy a property in Texas.

That would be glorious...lol quite honestly to get a longer contract and have them turn into longer term tenants provided they are good of course.

Landlords and Investors are concered about evictions and what that may look like 9 out of 10 times.

If your friends have a rental they should hire a tax professional. 

Is buying a rental into a living trust a good idea?

The tried and true version is pulling a list of properties whether you're targeting distressed homes or high equity homes in which case you can pull on something like Propstream or Propwire, you can skip trace through them or someone like Prime Tracers which has a pay as you go system. 

That makes your bookkeeping easier, and it can also provide liability protection if you hold title in an LLC.

I always like seeing new concepts for housing that can be used for various populations.

That is like walking into the store to buy juice that is for sale for $5 and paying them $7 for it because you want to pay more than what the juice is worth.