The Vendor refused to accept any responsibility nor was willing to be involved in any action to remediate the situation.  

I am willing to pay $100 to have the well water tested...but if test comes back bad seller would be responsible for a remedy, which is I have no idea what.LOL.

The rents are under market on all units (which I intend to re-mediate ASAP).Behind this property, there is a concrete parking area with 5 spaces. 

. - Inspection is done by the city/township, so as long as you're working with a licensed GC, it's fairly straightforward; it'll just have more line items due to extensiveness of damage that has to be remedied. - Also, most Restoration/Renovation companies that specialize in rehabbing fire damaged properties will use a web based tool called Xactimate for a comprehensive scope of work, which may at times be, as long as 300 pages.

So now the house is flagged with a failing tank and the seller does not have the money to remediate.

Jeremy - I do not have the exact answer, other than get multiple quotes on remediation.  

If a landlord notifies a tenant of increase in rent or starting to pay utilities previously paid by landlord and the tenant does not comply what remedy does the landlord have?

I tried every known remedy and recommended product for getting rid of the cat urine smell and none of them worked.  

Per my state's tenant landlord act, it says:"Except as provided in this chapter, if there is a material noncompliance by the tenant with the rental agreement, including material falsification of the information provided on the rental application, the landlord may deliver a written notice to the tenant specifying the acts and omissions constituting the breach and that the rental agreement will terminate upon a date not less than ten days after receipt of the notice if the breach is not remedied in ten days.

It is best that you do work with a local attorney to create a bespoke agreement that reflects your personal risk aversion and concerns going forward.