Early on, these mailers were getting returned, so for now I have stopped mailing to both these categories until I have found an alternative solution.Any advice from personal experience is greatly appreciated.

Ask for their tax return.

I think to accomplish my goals on this one I am going to have to 1)keep trucking along slowly now that I'm back at full health 2)find someone to "buy-in" with equity on this property as a return or 3)sell it 

Make sure they are local and trustworthy people who will return your phone calls promptly.  

I found a few properties for under 100K that can cash flow 1000$ every month.How can I get financed for an investment property without having 2 years of tax returns from my new business???

John Sheil Using the equity you pull out as a down payment will both help you improve your return on investment and leverage into better properties.

I fill the tank before renting, then they keep it full and return it full before leaving?

You can ask them if they'd be willing to come in on it with you if you give them majority (like 60/40) in return for them walking you through some parts that you're unclear on.

Jim Carson, congrats on not having any mortgages, I am aspiring to get there as fast as possible (numbers can never fail with cash on cash return).

If so a secure 5-6% return might look pretty good.