Why the anger, condescension, and self-righteousness?

This person also has more of a criminal history than they let on, being convicted in the 2000's decade and having arrests and charges even up to 2018, some of them for things like DV, making threats, drug/weapon possession, and driving without a valid license, although on the more recent ones they may have been found not guilty.

Also, if you do sue someone, it should be the buyer, as you assigned the contract to him and should have an assignment contract, which is your legal 'weapon'.

Personally, I think getting the names and addresses of absentee owners - especially if they have owned the property for 10 years or longer and are out of state - and sending them a carefully crafted letter is a good weapon to have in your arsenal. 

They went in weapons drawn with a K9 because the guy had a couple of warrants.

The tenant is really pushy and self righteous - now threatening to sue because I will not order a mold inspection.

Self-righteous much?

Having a handyman nearby has been our secret weapon to help assess bigger maintenance requests.

And they own weapons and will threaten you and yours.

I had a RE license in Cali along with my GC license to help in doing flips, etc.....It had zero impact,Now if you want to add a big weapon to your arsenal, get your GC license..... :-)