I have been driving by parks that easily are twice that price and alot of them are in pretty dicey areas, i.e. no jobs, drugs, cars on blocks etc etc.

Definitely share with the sheriff the situation with the tenant (guns and drugs) if it comes to a set out.You clearly what him gone but long term paying tenants are the things that real estate wealth is built on.

I was struggling with finding the right amount of empathy and firmness to handle my relationships with unstable, often drug-addicted property sellers.  

RCG has been training "Lonnie Dealers" for about three years now, less than one year seriously, and we spend considerable time on teach LDs how to approach and enter into joint agreements with community owners.A community manager is not the same thing as a community owner.

The seller's agent drug her feet in getting back to my agent and missed promised deadlines.

Just like a Toyota dealer is going to sell you a Toyota and not a Mercedes. 

Go to a local mobile home dealer and tell them you have a lot for sale and your want to owner finance the land.

The wheeler dealers and the Turnkey pushers tout 2% like it means the property is profitable. 

I am assuming you went out to a local car dealer ( whether new or used) - not knowing the salesman (or woman!)

These types will never be professionals, they lack the mind set to be in business, they are the wheeler dealers, the back lot car salesman, the door to door brush salesman, the "music man" who sold parents on his "think system" to play band instruments.