The tenant was using a portable A/C borrowed from family that was keeping the apartment relatively cool while the central was out, so I didn't discuss buying one then.

If you buy and live it , under FHA rules and guidelines you (the lender) can leverage the rent payments from the other side which decreases your DTI and increases the amount you could borrow. 

When you BRRR the property, you rent it , you do not sell it , your rental income after expenses is subject to ordinary income tax but not considered self-employment tax.Scenario 3: ( Which is the scenario you fall under) Your cash-out refinance is considered borrowed money from the bank and can not be taxed.  

@Zachary Penn HELOC can be an awesome way to borrow against what you have to purchase more properties and build your portfolio.

Not to rain on your parade, Gabriel, but it is almost always a bad idea to borrow money from family and mix business and blood.

How are you identifying loans that will have borrowers that aren't going to fight the foreclosure, go bankrupt, etc.? 

Due to the global pandemic going on, we are expected to receive less money back from our borrowers this quarter.

How many points should the borrower expect to pay? 

Taking over the payments is not something I'd necessarily recommend, not to mention many residential mortgages are not assumable...meaning, they can't be transferred from one borrower to another. 

You could borrow some of the purchase price and use your HELOC for the rest.