I would just add that when you do go under contract; have a general contractor with you (if you don't know what you are looking for) during the inspection period to give you a ball park estimate of how much things will cost.

Paper assets also are not very tax efficient .

Additionally, I would set up a acquisition an rehab line of credit to leverage funds so oyu can by more in a shorter period of time.

Pay for the option period.

Thinking that I could give him a 4 year period to stay in the apartment and have a balloon payment after 5 years and refi after he moves out. 

In my opinion starting with a house hack is the most efficient path forward.

I’ve seen many a deal that came to us because the bank couldn’t get comfortable with the lease up period on a new project and the borrower lost months having to start over with another bank.

There is a pretty steady flow of available multi-unit properties there (many more than areas of Cobb with decent schools) and in areas that I personally would consider reasonable to live for a shorter period to house hack.   

The excessive obligations in relation to income - the buyers agent also confirmed that no accounts or loans were taken during the period of 23rd July (pre-qual letter date) and 21st August (Denial Letter date). 

There you at least get to walk the property before buying, if not have a due diligence period.