Over the past several weeks, I've been doing a lot of research and analysis of how the crisis may create new opportunities (and amplify existing threats) for several retail categories as well as for retail real estate investors. 

Your best bet is to simply accept that you're not going to get the security deposit or to work out a written arrangement with her and give her forceful reminders when the payments are due (not forceful in a physical or harmful way, but in an implied threat way to let her know that you're serious).

I have had plenty of bad contractors but it never has gotten to swearing and threats

I don't see large numbers of people crowding into bars, restaurants, airplanes, and casinos until the threat is reduced. 

@Ken Eck I kept getting letters from the HOA about leaving the trash can out, leaving it at the side of the house, length of weeds at the side of the house...and threats of fines.

Only thing I would add to this good comment is his goal should be to get him at least neutral since he is an ongoing threat to your funding and your partnership.

They are getting squeezed right now with the threat of non-payment but they still have to pay the investor who holds the note. 

Her family has also become involved with some very sketchy characters in the drug and sex trafficking trade that have made threats to the property jeopardizing the lives of anyone coming and going from the property.   

I plan to sue this Seller and so does the Realtor because he's being belligerently ignorant at this point despite the threat of litigation.

Basically if there isn’t a police report with drugs, guns, or threats you are out of luck right now