This was a direct buyer-seller transaction.

They can stop the transaction with returning their money since no lease is signed. 

As a fellow Investor/Agent I use a low cost brokerage, like Equity, where you pay a small flat fee per transaction. 

Many real estate transactions are cash deals, or they climb way past asking price if the property makes it to MLS.

Then there’s all the transactional stuff...inspections, appraisal, working with the lender, coordinating with the title company, making sure the contract is executed correctly.. the list of ways a realtor provides value is long.

What sorts of loan products are available to me?

(current goal is create & convert 1000 leads/mth and close at least 1 transaction/mth).- Have not been able to find the right telemarketer to call the leads I'm currently generating.  

The title insurer, not the seller's lawyer, would be insuring this transaction ...  

This is an even lesser known product than either FHA 203k or Homestyle. 

I suggest you remember that maintaining a rental property is a business as well and your emotions should be separated is such transactions.