You can never force your way in...even in an emergency. 

The only con I can toss out there is most want to mail their money which forced me to get  PO box.

When the unit failed the inspection, she should have been given notice and forced to move.

Additionally, under this policy we would be FORCED to have a management company if you live outside of Allegheny County.  

If she doesn't want to live there anymore, you're not likely to force her to stay.

Is investing in a duplex unit that has oil heat on one side and forced air on the other side a good idea?

Nobody's going to force to purchase a whopper!  

@Wes Eaves I've had two different insurance companies force me to replace 3 breaker panels this year and a driveway.  

I tried to show it in the first 2 pics, but I'm not a great photographer :)  We decided instead of forcing our craftsman design on this street, we'd try to blend in a bit. 

Fear will force you to take calculated risks, so as to mitigate or minimize any possibility of financial loss.On the other hand, too much fear can keep you idle and on the sidelines, and that mindset must be avoided at all costs.