It was all really quick, and the time to complete everything happened a lot faster than I expected (which was a good thing).I was worried at first that I had to use all the partners that Rent to Retirement had, but it was really easy for me to shop around for different lenders with different terms and rates, insurance providers, and property management company.

Loan interest is deductible based on it's use-not the asset securing it. 

We're not aware of anyone that's made a purchase from them work in over 3 years:(Most of the incentives in Detroit are targeted to owners that will live in their home or developers targeting large projects.

A particular strategy that may help you is to assume VA loans.  

States which DO NOT require licensing for originating or negotiating a loan secured by commercial real estate nor a loan secured by non owner occupied residential real estateALASKA ARKANSAS COLORADO CONNECTICUT DCDELAWARE FLORIDA GEORGIAHAWAIIIOWAINDIANAKANSAS KENTUCKY INDIANAKANSAS LOUISIANAMASSMARYLAND MAINEMISSOURI MISSISSIPPI MONTANANORTH CAROLINA NEBRASKANEW HAMPSHIRE NEW MEXICO OHIOOKLAHOMA PENNSYLVANIA RHODE ISLAND SOUTH CAROLINA TENNESSEE TEXAS WASHINGTON WISCONSINWEST VIRGINIAStates which DO NOT require licensing for originating or negotiating a loan secured by commercial real estate but DO require licensing for a loan secured by non owner occupied residential real estateIDAHO MINNESOTA OREGON UTAH VIRGINIA States that DO require licensing for both residential and commercial real estate loan origination and brokeringARIZONACALIFORNIAILLINOIS MICHIGANNEW YORK NORTH DAKOTA NEW JERSEY NEVADASOUTH DAKOTA

(Either with the roofing company, a heloc, or a personal loan.)Either way you will probably be way ahead on interest saved unless you have a sub 6% interest rate.

You can still find single-family homes in the $80k–$100k range and duplexes in the $130k–$150k range, even in C and C+ neighborhoods that are seeing steady improvements.

To qualify for non-recourse commercial loans through Fanny and Freddy you have to have equal new worth to the loan amount and 10% liquidity. 

But IRS allows an IRA to be invested in anything except life insurance and collectibles.

It would cost me $13,835 to get down to 6%, which would give the best value over the course of the loan.