In FL I had a guy who confirmed my criteria and then was upset when I denied for a criminal issue in the background check...because he plead 'no contest'.

Otherwise, the criminal case can serve as evidence in suing them in small claims court. 

It's better to just not have a stove in there -- the triggering offense for most city code violations -- and do a coffee bar, etc.

Anyway my question to you all, especially the criminal masterminds here on BP, is how can I really mess with these scammers?

What if that access were given to criminals?

Three different management companies have said three different things.Fines are generally either $X or Up To $X for a 1st offense.

No offense, but your lack of experience is showing. 

or criminals that will jsut case the houses and come back and steal everything.

Permanent debt commercial mortgages also generally will not play with an in-place DSCR below 1.25% (possible exception for very strong/experienced borrower, but such a person wouldn't be making a thread like this one, no offense. :).An interesting result of the 1.25% DSCR being more firm on the commercial side is that rent-to-price ratios and cashflows are better.

No offense to the other posters, but this is all terrible advice.Terminate the lease and get rid of these tenants!!!