But they tend to have a revolving door of entry level employees and rely heavily on tech.

You'd be surprised how evolved it cam become in just a matter of months. 

I can't imagine a bank giving me a second look without a large lump of cash in a checking account and some revolving debt paid off.Not to mention a run-down four-unit doesn't intimidate me but I don't know a way to fold repairs into an FHA loan so they would have to come out of pocket right?

Pay off any revolving credit accounts.  

Doing an unsecure loan to a friend who is trying to consolidate revolving credit card debt is a bad idea!

Quote from @Brandon Allenczy: I try to prevent situations like this because they become revolving doors and you lose control over who resides there.The most I would do is add the new tenant for six months.

There is 9.25% left for wiggle room from the income to get to 50%.9.25% of $3,466.66(Income) = $320.66There is room for about $320 of other revolving debt like a car payment, credit card payments, etc...Obviously these numbers are very estimated but I wanted to show the math.

.-- Have a home inspection done by an inspector that does 2 to 4 unit rentals like this, including a sewer cam.-- Pay particular attention to the electrical system.-- Verify cash flow<---(that).-- Use Estopple Certificates.-- Check for liens.-- Get copies of all leases and read them.-- know if the city is going to make you replace degraded driveways or garages or etc... upon takeover.-- how much service life is left on the roof--does it leak (???)

No it's a true revolving credit line secured by property though. 80% LTV 6.5% currently variable monthly 3 year term.

A HELOC is a revolving line like a credit card and usually do not have closing costs.