It's more harmful than good, the level of benefit is networking.

First, do no harm is officially out the window. 

Person harmed already filed lis pendens - they have to prove the case then get judgement then lien the property but the filing holds up refinancing or selling. 

They suffer no harm, you do.

Seller's credit harmed for 4-7 years.

Nonsensical policies by AirBnB that harm the hosts and allow bad guests to get away with non-payment4. 

I don't know the legal requirements in your state for disclosure but I do agree that you can open yourself up for some liability if the stalker doesn't know the previous tenant moved (a bad stalker at that) and harms the new tenant.Def. check with state laws on this topic and would let that be your guide. 

Do people think extracting oil from other countries that have no standards whatsoever is less harmful?

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.

That said, whether that or another degree, nobody was ever harmed by having an education, and it often opens doors you may not otherwise get through.