Thank you Gary.As I re-read the thread, my post about knocking on the door and threatening to sue sounded harsh out of context.

On my way to the property she then calls back to say strangers are in the house and one threatened to kill her.

Any pushback, just start eviction...WHat I would bet they will do is play back and forth with you, family chat, threatening law suits, and then back to family boo hoo... drag it out. 

If a major employer in the area is leaving or threatening to leave and it could lead to further vacancies, your rent value "could" go down.  

They then start threatening legal action if I don't give them the security deposit and write them a letter of recommendation to move into another place.

Unfortunately, at this time she started threatening to call the health department, saying that the pests were causing her son to have asthma, that we paid people under the table to have it pass inspections...it was a lot that was relayed to me via our PM.

We had to point out several mistakes that were made, one of which they didn't address until we threatened to kick them off the project.

I know I could threaten to move our office, but that is a huge undertaking and fairly unrealistic in a town our size.

But though the mortgage co also allowed sale or ignored it, and now mortgage is null and void  they're threatening me.  1, do I file paperwork if intent to redeem? 

Not sure I'd take the threatening approach out of the gate.