In Maryland state does the motivated seller have to a written statement giving me permission to assign the agreement?

We can motivate eachother!

There is a site that reviews/rates turn key providers that would help with your diligence.An other option may be to partner with some one here in the area where you want to invest and they could be your boots on the ground sort to speak.

After all, if he's not motivated to get rid of it then this is all just a fun hypothetical.

In my opinion, these are most likely experienced investors and more than likely they are not motivated to sell, especially since they haven't owned the property for too long. 

I appreciate your input, I'm using all info as motivation & a heads up on what's to come.

@Karen Margrave, He doesn't need the lump sum on a sale, but he does expect some sort of gain over time that we need to define.

You need to have some sort of criteria/expectations on the property before you make a decision. 

They may not be doing this with any intentional motive.

This will give you a full suite of solutions to offer a motivated seller.