Having documents confirming communication with several lenders and refusal of a loan, you have grounds for returning the deposit.

What @Chris Seveney said.As soon as they make these kinds of accusations, inform them that henceforth all communications will need to be through your attorney. 

I think it's good they are communicating.

Also would consider getting a POA from the seller for their loan so you can communicate make payments on it.

Instead of denying them, can we refer them directly over to the owner for them to sign a lease with the owner who is willing to effectively manage the contract, payment and relationship BUT would still want to retain us (albeit for a lower fee) to deliver ONLY guest and property care activities (guest communications, organizing cleaning, lawn and pool care etc). 

If she was communicating with me, then she wont be out on the streets.

Make sure you have all your communication.

I know they have both received their respective letters because the upper tenant responded promptly with the contact info I requested.Upper unit tenant has been awesome and super easy to communicate with.

Get authorization to use them to reestablish communication if she is ever incapacitated, incarcerated, or deceased.

Money --and the lack of communication around money-- is the largest cause of divorce.