Another problem a home owner faces is where are they moving to and how soon does he need to move.

He diagnosed my problem as a faulty control board.

Haha, my realtor buddy said there shouldn't be a problem as long as the sellers were the title owners.

I don't think that getting materials will be a problem, as lumber prices are going down and new home starts have decreased as well. 

This poses a serious problem as the incoming tenants have typically given a 30-60 day notice to their previous landlord so they are almost always under a time crunch and may have already made arrangements with moving companies and utility companies. 

I don't think the communities are the big problem, as like you said they have appreciated quite a bit in recent years (though appreciation only goes so far if you can't offload them), especially as more folks are moving back into the area.

The values here in DFW are outpacing rent growth in a lot of places which can be a problem as well.

My non-essential tenant asked for a 2 week extension on the water bill, which I agreed no problem, as he's been an awesome tenant.

I believe this is more a government problem, as they need to provide better programs or more incentives for non profits and investors to help seniors and disabled (mentally or physically) with housing.  

As long as you don't let the fear overwhelm you into a state of Analysis Paralysis.... then it becomes a problem.