I do appreciate all the things you brought up and i was kind of considering the duplex for the purpose of just getting into it maybe i should start slow. 

Our next purchase  has two purposes.

It becomes clear pretty quick when a property is underwater on the first and not worth bidding on.Never trust anything from an auction company website because if you read closely enough you'll find that in the other print (often in bold) is a statement such as "for information purposes only -- buyer must independently verify all information" 

I have a very basic understanding of corelogic and listsource relationships and purposes, but not why they would be listed in those fields.

Because my current apt (soon to be listed) is a rental property I have to buy a single family, condo or a duplex for rental purposes to qualify for the 1031 exchange (to pay little to zero taxes on profit). 

@Loan TranGenerally speaking I think becoming an agent with the purpose to become an investor isn’t worth it.

I actually ran my own comparable properties report before the appraisal, using several recent sales near/around our subdivision. 

You can compare the existing use with the allowed use(s) and see if there's any opportunity.

Quick story on me, I became an accidental/on-purpose landlord with my first home purchase.

In our world, regardless of zoning, 1-4 units are "commercial" for financing purposes if they are non-owner occupied.