Our contract clearly allowed us to get a full refund of earnest money if the seller was not able to get the title insured, so we had very little risk.

So, does it have monthly cash flow or is there a notable appreciation potential, or...what does a particular property offer in terms of returns? 

Equally notable....there are all kinds of home warranties. 

I have bee watching our local market very closely, am not able to draw any conclusion / 's on why my property is not selling.

Were you not able to use an FHA loan on this property because it was FSBO? 

In these markets, eventually you are "investing" for appreciation (with notable exceptions - $50/unit does not qualify as cash flow IMO).

I completed the real estate broker class in 2006 but was not able to complete the state exam due to a family hardship.  

Are there any notable differences in approach that should be taken with Fannie or HUD (FHA)?

A notable example is when I bought 120 houses in the San Francisco Bay Area from 2010 to 2012 at the depth of the last cycle.

It may be the door jamb has been damaged from getting forced open repeatedly, and/or having partial, poor repairs done; or improper screws were used to mount the hinges at some point, easily pulling out or just not able to be secured adequately.