I certainly Do Not know it all and will never be able to learn enough even though I continue to be a student seeking knowledge always.   

Great tools that get updated regularly.I am on the lending side of things and would be happy to hop on a call with you anytime to discuss financial strategies and help answer any questions you may have about nearly any loan product available to help you on your journey, even if they are not products my capital partners offer.We are all here to help you learn and grow.

I refinanced it into a  5% 30-year mortgage with a local bank as the seller would only carry the loan for a year.

Is it best to just throw cash flow at the loan untill the principal is paid off (current cash flow between the two properties after interest and all expenses are paid plus vacancy rate = about $250 left monthly) refinance at renewal to pay it back in full? 

Early in my career I worked on cattle ranches, then started doing farm and ranch loans for seven years, and now have been doing hard money lending and other real estate investing.

Quote from @Burke Atkerson: With over a decade of real estate investing experience and over 100 flips, I now provide private money & hard money loans.

@Robert EllisAre you leveraging construction-to-permanent loans or private funding?

You can get a normal owner occupied home loan to do this. 

Investment Info:Single-family residence private money loan investment.

If that's what you're really after I would start with the basics of what kind of bank loans either residential or commercial are available to you - not saying this is the best option, but it's a good place to start.