There is no limit to the number of non-conforming (fannie/freddy) loans you can have.

We have a very rigid policy when it comes to placement and screening, it ensures that we follow all the rules every time equally with every potential candidate, discpline... the short answer is, if you feel this is a "qualified" situation for your business then pursue it, if you feel the decision is not emotional, not monetary and conforms to your policy....... you have your answer

No FHA and any buyers would have to get a non-conforming loan with 25% down.

I bought a fourplex plus non-conforming attic unit in New Orleans in March; I put 25% down and was cash flowing $1300/mo at the onset.

A clear, no-gimics lease where the tenant performs absolutely zero maintenance and has no authority to change the property and no confusion over who owns and retains responsibility for the habitability and conformance of the property. 

One of the key factors to being grandfathered in under a non-conforming property is - is the property vacancy or occupied, and for how long?

College doesn't teach you "how to learn" it, like all other schooling teaches you how to conform.

So my statement relates to mom and pop wanted to buy a home or a 1 to 4 unit with federally conforming loan product.  

A professional is someone that conforms to technical and/or ethical standards of a profession.

But we have to be careful though on framing the investor self-righteous on his opinion, I think there are two types; the one who really is very knowledgeable and really narrowed down his investment criteria to the T and works with what he feels conformable already knowing what is require on the others RE niches ( for this type I will not consider him self-righteous because clearly is his niche and domain and terrain.