If an individual earned a decent base income from a FT job (relative to the area), then doing owner occupant maybe 3 times in a row, for example, should not a problem...

There are 2 main tax reasons why you will want to use an S-corporation.1) Flipping houses either individually or through an LLC will generate self-employment income, which is subject to a 15.3% tax. 

@Michael Pursell following up on @Charlie MacPherson good comment you also may want to pay attention to the exact wording of this stuff and how its individually interpreted by the various building departments: Accessory Dwelling Unit, In-Law and other terms may mean something slightly different town by town and be treated differently, likewise if you owner occupy or not. 

We are looking to spend a considerable amount to generate direct mail messaging that works in Columbus and Cincinnati.

As Chris mentioned, know the individual state laws.

I would not contact banks individually and instead let a broker tell you what you can qualify for and the best interest rates.

In FL, my wife and I turned our individual houses into rentals when we bought a house together that also had a carriage house so we had 3 rentals.

Legal can come later, especially if you are purchasing multifamily as an individual. 

The way I see it is the rentals I am looking to purchase will generate cash-flow and any appreciation is a bonus.

The fact that someone is able to look at two paths (Wholesaling & Real Estate Brokering) and is not smart enough to see which one has more income generating opportunity tells me that they aren't sophisticated critical thinkers.