Per my realtor of the three, fuel oil is considered the least desirable.

I am still wondering what makes larger apartment buildings more desirable than smaller, or what the pros and cons are of each...

My personal and investment goals/desires are to be home more time to enjoy life, spend a lot of time with my kids, not worry about meeting debt obligations all the time, excercise etc.

Two appraisals and a home inspection is the norm these days and that's a lot of professional opinions.So I suggest being prepared for the possibility that if you compromise it might not get the desired results anyway.

My search stemmed from the desire to get paid online and find a software that would allow me to scale my business.

The highly desirable areas of DFW are not producing many cash flow positive deals, simply because market rents haven't caught up with property values. 

Sounds like from earlier posts others were looking outside this market for better neighborhoods but there were some improvements being made that may increase the desirability.

There is a good chance they will move out on their own when they realize they can't live the lifestyle they desire on your property. 

but inform your realtor of your desire to close with as little cash as possible, thus requiring a seller credit. 

Well is an easier eviction a desirable outcome?