The county I live in has 4 Amazon warehouses and industrial land is through the roof.

I was on the roof of my home for a few days and ultimately made it to Lafayette, La.

If you don't have the down payment, how do you expect to fix roof repairs, replace a furnace, and water heater, and small repairs that are needed?

For instance, a new roof is $10,000 or more in a lot of places right now.

Also are you factoring in some turnover costs and recurring capex (like a new roof every 25 years)?

Make sure you include the cost of the new roof.....

(i.e. they may have back rent discharged by the court, but they are still living under your roof.)Aren't there other applicants whom are qualified that will rent your property? 

They have their drywall guys, their carpenters, floor guys, roof guys, etc. 

Replaced roof, updated electrical wiring, radon mitigation system What was the outcome?

This 4plex is in a class C or D neighborhood (not exactly sure which) but my realtor and I saw the potential in it due to the cash flow/COC numbers we calculated and the fact it had a ton of work done to it in 2017 to get it to decent shape (all new electrical, furnaces, HWHs, renovated apartments, new roof, all doors and windows, etc.)