No matter what you do this tenant seems destined to try to frustrate your sale. Tenant is free to mouth off to anyone willing to listen. Frankly I'd not engage him in a debate about asbestos --your insurance company might just drop you because they want no parts of problem tenants either! And if you have a "reqular" homeowners policy on a rental unit that may be totally wrong tool---and you are inviting problems to open debates. Me, I'd just shut up and do nothing on insulation topic.
I'm happy to be retired from most of my residentual rentals.
What kinds of other problems with tenant--like not paying rents? Or stuck with low rents?
While I'd try to avoid winding up with an empty unit that needed to be heated in dead of winter , I would make my first priority the termination of the lease and eviction of this tenant by whatever mechanism is legal to use.
As an aside--few buyers want a problem tenant either!