- What options are available under state law that provides me with some amount of security, as the seller, once the deed is transferred to the end buyer upon signing of the contract, in the event that the buyer defaults on their payments? 

Pine Bluff has one of the highest per capita crime rates in the country and several of the school districts are under state control.

In the case this partnership with the other couple turns sour, the hope for the best but plan for the worst can't be understated.   

Any owner can self manage their own property under state law. 

The land value is probably less than 20% of the purchase price so your depreciation deduction is probably understated.

When I've looked at these I can usually spend 15-30 minutes researching the offered properties on the internet and discover that they're overpriced and the rent is overstated.Very consistently sellers will understate expenses.

The current C/D is a mandatory form under state and federal law (every state).So, until states and federal regulators mandate forms for private/hm lenders, you won't see it.

Who can close a real estate transaction under state law?

Sellers often understate expenses to support a higher price.

If you know what you are getting in to and understant the risks and rewards, you can invest anywhere.