Well we were over there the other day to replace all the batteries in the smoke detectors and noticed that it had been removed...Besides being rough on the apartment, the other tenants have told me that he's yelled at them numerous times, slammed doors right before they could get to him, etc.

A lot depends on the health and housing dynamic of the town. 

Health club.

Tommorow I am going to visit my first commercial property 4 apartments, 1 retail space and additional revenue from billboards and a future cell tower (I need to get details on this) I am not sure I want a cell tower on my building from a safety and health standpoint?

That's a health and safety issue.

The rehab project has been somewhat started but can no longer be completed due to health issues.

If the unit is messy/dirty to the extend of being damaging or a health hazard, our lease also gives us the right to send-in a cleaning service at the tenants expense.Your biggest concern as a landlord will be vacancy - both physical and economic - as vacancy is foregone revenue.  

To your health and the winner's wealth.

Does anyone have tips/resources on navigating this scenario; finding a good broker, questions to ask, key analysis to run to compare properties and gauging local economic health?

After getting married and adopting a newborn baby, I recognized the need for the health and life insurance benefits of a full-time position and hired on with Tandem Computers in 1992 making a six-figure salary.