We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

Perhaps that was a mistake in hindsight, although I was prepared to counter anyway, so maybe no harm done.

And if it still comes as a surprise to someone, what's the harm?

From my perspective, there is no harm in having a license!

So it’s ok for a perspective tenant to expect a landlord/home owner, tonallow a stranger into their house but not ok for a home owner to ask who they are letting inHmmm I think I will risk losing the people who are afraid of being scammed instead of risking bodily harm or allowing someone to case my home so they can come back later and steal the appliances 

I am not a do-gooder and I could really care less what these people do, since it doesn't harm me.

Any thing you say to them about this issue may harm your case so do not discuss this with them any further but ask for the name of their lawyer and phone number to give to your lawyer.

However, if you have ever bought a house at auction (@Hal Thompson has so I'm sure he'll concur), or seen the inside of a just foreclosed house before the bank has had it cleaned out - well, there are lots of owner occupants (not just renters) living in conditions that are similar, and attributing the situation to substance abuse is just stereotyping and might not be quite true.

Second hand smoke is ghastly and harmful to the health of others, so consider this if your property is multifamily or close in proximity to another. 

If one is paying the rent, no harm, no foul.