Many Buyers and Buyers agents here are skeptical of the "Joe Schmo" homeowner who "took care of it himself" so as others have suggested, for peace of mind when you sell it I would have a clearance test or air quality test performed by someone so you can show it was remediated correctly and 3rd party test results show that. 

Bring in a good contractor and get firm estimates prior to closing this transaction.Also keep in mind that while the realtor may be competent and honest in her evaluation of this being a good deal, she stands to make a $12,000 commission upon the deal closing so she is not a disinterested 3rd party.

Let's keep this party rolling.

Either party can terminate the lease with a 30 day notice.

The latter is unlikely if you are a bonafide 3rd party buyer (BFP).

They are probably unhappy with the home inspection they got and want another third party.

The rest of his philosophy resonated with me pretty deeply so that makes sense that the part I found discordant probably just arose from me misunderstanding his intent.

Call the locatin manager and tell him what you're looking to do and that you're looking for referrals to builders.Vet each party in the process carefully.

I suspect they may have paid a 3rd party to scrub negative reviews.  

No need to go to pay sites or 3rd party companies.