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.

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.

With the knowledge and financial means to purchase an investment property, they are not an incompetent person; based on how courts normally examine the situation in which you present.The fact that the PM keeps the late fee also doesn't harm the LL, because the LL is still getting their same amount of rent as is guaranteed to them in the agreement.

Rather, out of a feeling of responsibility to my former tenants, who I happily provided positive references for.The reality is that it does a landlord no good, and could do harm, to respond to a reference request.I have also gotten calls from landlords lobbying for a statutory and regulatory change.  

The police don't remove people claiming tenancy rights unless they are an immediate physical harm to themselves or other.  

Nothing is offered to cause harm to anyone, but may be useful in your situation.

There would be no need to take this matter further legally and if so, could cause more undue harm than intended.

You ARE responsible for the harm your tenants cause neighbors.  

Asbestos is only harmful in it's friable state, option #1 therfore to not touch if it's in good shape.