He said that it is severe, but easily remediated.

He is not a mold remediation/abatement expert.If you did not approve any work and he did it, that is on him, it is called unauthorized work, which is never paid.

Of course a professional foundation expert will recommend work to remedy (that is how they make money).

They should also be able to tell you if there are any current remediation issues at the property as well.

It depends on the state and local landlord tenant laws and what remedy a tenant can ask for an uninhabitable unit.  

I thought about including a contingency for MA Title V approval (or at least a remediation plan), but that might not be necessary because I already suspect that the septic is failed, so why waste money on an inspection, right? 

With the flooding from Sandy and Irene you really need to do your due diligence on the property to see how the property was remediated, if it did flood, after the storm.

I kinda have an issue going on. hoping it get remedied tomarrow evening. but i had Fundingforflipping contact me, had me do the creditnav thing, told me they would get back to me the next day-  and they not only went dead silent, after 14 attempts of mine to contact them and they even promised to return the message or call-    totally ignored.  

Any other ideas to remedy the problem?

If the breach is remediable by payment of rent, the cost of repairs, damages or any other amount due to the landlord pursuant to the rental agreement, the landlord may give the tenant fourteen (14) days to remedy the breach.