Assuming he actually got the majority of his capital back in each of his 10 or so BRRRRs (which seems to be the case) he's likely accumulated a good amount of equity and is benefiting from debt paydown and tax advantages (with potential appreciation and improved future cash flow once the properties are stabilized being nice-to-haves if they happen).

I used to have several out of state investors who would buy houses in Memphis via the online tax sale auction, then hold them for a year so the redemption period ended, then they would hire an attorney to "quiet" the title which would take 4-6 months and cost roughly $5000 but then they had clear title and would sell it "as-is" to other investors or hire me and list it on the MLS and get higher offers. 

And further, if it's the tenant who decided to stop negotiating in-house, why would any of that cost be on the landlord?

If they want 78 degree temperatures with windows open they will likely have monthly costs of $3-400.

.- Process for analyzing/screening potential deals.- Anything else that is relevant to the individual.

As a bookkeeper here is what I tell potential clients. 

Granted, I didn't pay for them so maybe my palate was skewed a bit as those that were sharing - I had several hard core collectors as customers turned friends -  they were often proud to share the price and method of obtaining, but I just don't feel the cost was worth the taste.

Anyone have any thoughts on Alabama as a potential market? 

Typically it will cost a point but it’s better than hitting maturity and then have default interest kick in.

As a general rule, it's best to learn how to handle problems before they become problems. make a list of the potential problems you could face as a landlord: rent rates, marketing, collecting deposit, late rent, unpaid rent, abandoned rental, early lease termination, unauthorized pet, etc.