Regardless if the contract is a standard Realtor contract or a builder specific contract, there are usually a few clauses in the contract outlining scenarios when the earnest funds can be returned. 

@Jacob SampsonI see what you are saying, but there are not very many people who would buy a life estate subject to an 85 year old's life span.

Pickens if you transfer title without paying the loan off you may be subject to a due on sale clause.

Anyone have any book recommendations on the subject?

I look forward to reading more on the subject.

Is there a way for me to purchase the existing note subject to the existing loan without disturbing the lease to own contract in place?

Sounds like the arrangement you are discussing is called "Subject To" where you can quit claim the property to the new owner but leave the mortgage in the sellers name.

@Marco MorkousThe source is called hard work to find borrowers who do not want their house and you would take it subject to.Is the reason you can’t get a new loan because of your credit?

I'm looking to lend on a deal, and they don't have an LOI outlining the terms of the deal that can be signed before money is wired to the closing agents escrow account. 

I'm not sure where you are in your research, but biggerpockets is definitely a great resource on this subject. 1.