sometimes your gut feeling is a good indicator that the deal isn't as great as it appears to be. 

Usually, if there was enough water to cause a failure in the drywall, there would be a noticeable stain area.That said, the ceiling looks a bit rough and doesn't appear to be an intentional/decorative texturing.  

As far as mortgage, Since you appear to be 1st timer and the banks will likely be looking at your personal income to pay the mortgage more than the rents you feel you would collecting and using towards your mortgage payment. 

It takes about 5 minutes on the clerk of court's site.

It doesn't go on their record, you don't go to court, and it is just a NOTICE to them that their rent has not been received.But even though it is just a Notice, it is imperative you send it to the tenants the first day rent is late because you can't even begin the eviction process unless that Notice has been sent. 

This way, it is considered rent and can be part of a rent court issue rather than a more difficult/separate civil court issue.

Please help me http://www.pwcgov.org/government/courts/circuit/Pages/Records-for-Occasional-User.aspx

As for the sub tenant if she has breached her contract you can have her evicted but court costs are no fun. 

I tried for several months to motivate them to let me take the tenants to court, but they refused.

With the door open, the controls appear to work as normal (power button and cycle selection knob appear functional).