I have found that they typically do not honor their leases or treat me right, and this is one of the red flags I look for when screening tenants.

This is incentive to pay.Self storage relies on Americans accumulation of personal property and the need to store that stuff.

The fact that he is reluctant to deliver it vacant may be a big red flag that the tenants are going to be very hard, if not impossible, to get out.

@Jeremy Christ The shop front being vacant is a red flag for conventional commercial loans, plus the loan amount is very small for commercial financing. 

What are some characteristics I should look for and characteristics that are red-flags?

This is a huge red flag and I would never agree to it.

@Jeff Plotkin I think I have a flat rolled asphalt membrane roof in Jacksonville FL that is insured with American Integrity.

@Zak MarinkoI think this may help you out:Income by neighborhood in Chicago (2018) with chart on the right showing income trend for Humboldt Park:Absolute population change by neighborhood in Chicago (2010 to 2018) with chart on the right showing population trend for Humboldt Park:Date used is from the American Community Survey (ACS).

This was my first red flag. 

  ( only 3 percent of American's save any money).Work and save and invest in Real Estate.