DEFAULTS Tenant will be in default if: (A) the Tenant don’t timely pay rent or other fees and charges they owe; (B) Tenant or any guest or occupant violates this Lease, property rules, or fire, safety, health, or criminal laws, regardless of whether or where arrest or conviction occurs; (C) Tenant abandon the property; ....When Tenant is in default, the Landlord has the option to declare the entire balance (all outstanding balances including but not limited to invoices, rent, cost due to damages/abandoning the property) payable hereunder to be immediately due and payable; the Landlord may exercise any and all rights and remedies available to Landlord at law or in equity and may immediately terminate this Agreement.XVI.

I have clients at my W2 who didn't do this and are now paying environmental remediation companies (like the one I work at) hundreds of thousands to clean it up, by order of the EPA, even though the PREVIOUS owner caused the issue.

There are three ways you usually remediate charring.  1) Replace 2) Dry ice blast or 3) Seal (but not with paint)

It is not a problem.There are different remedies, including soaker hoses and other remediation items, to limit soil impaction, but piers and leveling are common. 

There are a handful of options that could remedy some of your pain.1.

Kicking out a smoker will leave you, likely, with extensive remediation costs and vacancy during that period.  

I'm considering upping my aggressiveness on remediating this issue with something that will cover up the color of the mold so it will indicate better remediation efforts to future potential buyers. 

This is a fairly common issue with older properties  where root structures create a dislocation in the line causing constant backups and the only remedy is replacement.

He has 40 in another.Greed.... the only remedy without paying is for the senior lender to foreclose all those liens out . 

Educate them, give them time to remedy their mistakes.