Don't take this wrong or harsh but you are doing it backwards.

If you get a lender involved (and even if you don't) you should get a couple of things:1) Geo-Tech study - This is for the soil to be stable enough to build on2) Phase 1 Environmental - The person doing this will search title/recorded history for things like buried storage tanks or uses like businesses dealing with hazardous chemicals. 

Then they treat the tub with chemicals then with color coating.

When I say tools, I am broadly including processes, chemicals, machines, etc.

I like to learn as much as possible before I jump into something, hence my Chemical Engineering degree from Texas A&M University (Sorry, I had to throw that in there some way.).

It will include a manual more than 40 pages long establishing the standards, as well as specifying particular chemicals and other products to do the job."

However, if you are too harsh, they will think poorly of you as a landlord and it will be a difficult and contentious relationship to manage.I recommend being sympathetic to their concerns, taking the time to identify any legitimate issues - it's more than possible that actual problems that should have been addressed during the rent ready were missed, and there are certain things you can't leave "as is" per landlord-tenant law and your local housing code.

& you were trying/thinking to move two more people into the property.Sorry if seems little harsh, but from LL perspective I would say you aren't desirable tenants."

@Kevin SmithYou are not going to like my harsh opinion, but I won't sugar-coat it. 

This might sound harsh but I would never buy a business.