I am trying to determine if I should use the 3 property identification sheet, identify the physical address of the building along with my approx ownership percentage of the building based on unit count percentage.

If so, what formula should I use to determine MAO?

Fitness Determination | TREC (texas.gov)Good luck! 

What I did to find the owners was to first determine what zoning I was looking for, then I used property radar to search from appropriate properties. 

I'm trying to determine how much cash we'll have available to invest into the duplex.

Some accountant determines the rates based on risk and the computer just spits out numbers. 

They are currently rented out, although the 2-plex is owner-occupied.I'm not sure how to go about determining a market price though, specifically with regard to the fact that there are so many different types and ages of buildings.

The building was just inspected by a very credible engineer out of Columbus, Ohio and it was determined that the building is still structurally sound. 

However over the years the IRS has been very suspicious of such arrangements because of the opportunity for friendly parties to structure sales prices to shift the basis to benefit the exchangor. 

Most piggyback seconds require 721 middle FICO score and full doc (IRS taxes).