Just take a look at the real estate sector in general, as measured by the iShares US Real Estate Exchange-Traded Fund (IYR) .IYR data by YCharts This is part of the article.

Market Sectors I want to currently focus on are Apartment Complexes and possibly Residential flips.  

The low deferred maintenance would indicate a hold.Some of the things indicated by @Henry Clark can also be important - like moving into a different sector or geography where growth is projected to be higher.  

Back before I threw in the towel on trying to beat the market makers in the stock market and switched to straight indexing, I would always pick a couple of companies in an industry or sector that I was interested in to mitigate the business risk of any one company.

Right now I am on an early stage of defining the Concept or Basic Design, I have no problem at all with the arquitectural and engineering side of the Design but I have absolutely no clue about how to define the number of rooms, size of each unit, final user market sector and related subjects, so I would love to hear from a savvy developer about some general rules of thumb and methods to approach this issue. 

I said of course but unfortunately not in the education sector.

There is probably some good opportunity in the commercial sector in Ogden as well since it is growing, but it seems like there are lots of empty buildings and might take a few years for all those to get occupied!

Lots of good deals there, especially with all the growth in the tech sector in town. 

How, or why, should it be any different with purely private sector mortgages, since these are a legacy of the insurance industry?

Unless new companies are moving into that location, creating replacement jobs that pay similar wages and require similar skills, all that will be left are low-paying service sector jobs.