It is up to the Trustee to determine if your offer price is sufficient, that requires an appraisal, and the Trustee has to assure the court that they have not given you preferential treatment.

We keep separate income/expense records on each property in Excel, which is sufficient for tax purposes.

Tenant placing rent monies in the mail is not sufficient for rent to be considered paid.Basically, I want them to pay with Cozy and expect they will. 

You might be able to improve that rate a tad bit using one of the newer residential mortgage programs that base it purely on the property's own cashflow (some of them will go as low as 1.1 DSCR whereas pure commercial wants 1.25), but the improvement wouldn't be sufficient so as to be worth the hassle/fees/costs/etc, knowing that you're just going to be doing it again in a year or two when you have sufficient 1099 longevity to get a Fannie loan.

I've found that Arizona, Texas and most mid-west states give both good cash flow for rentals and sufficient appreciation for fix & flips.

@Jimmy Solano, although you "really like / prefer the 14 unit property", I'm not convinced that "its lower asking price" is sufficient enough reason.

If the savings did not seem sufficient, I might see if his parents could co-sign.

My goal is to pursue the BRRRR model as I want to generate sufficient income from multi-unit homes to allow me to expand my investing business into a full-time affair replacing my current 9 to 5.

However, while the results of your big lift may be lower operating and maintenance costs, if the local market will not support sufficiently high rents to provide a timely pay-back, you have over improved.   

FHA also has a rule called “Net Self Sufficiency” meaning the total mortgage payment must be less than the total rental income on the property.