He was previously my teacher in high school, so I've had a relationship with him and I've signed a buyer's agreement with him.

Hello, I have a townhome close to theme parks in Kissimmee, FL that is rented and on a one-year lease (was previously short-term rental).

I'm trying to figure out a way to utilize a large storage building at one of my MTR listings in Memphis.

I wish I would have known to do that in college and the years afterward. 

Using VA/FHA/whatever to acquire the property, personally occupy for ~1yr, then move to the next and put the previous into revenue production.

Visiting the property in person is beneficial too, as it helps you understand the flow of the house and assess how well it can be marketed later on.For turnkey properties updated by previous owners who lived there can be a good buy.

If you're accredited start researching potential syndicated deals- Some you can get in for as little as $50K; muitifamily, storage facilities, Residential Assisted Living..... 

Due diligence on the borrower should include a review of the borrower's previous communication patterns with previous lenders.I personally live this one with one of my borrowers, who basically ghosted me once they received the moneys from the loan.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

He was previously my teacher in high school, so I've had a relationship with him and I've signed a buyer's agreement with him.