If I pay $50 for the Sheriff to issue them a 3-day Pay or Quit Notice, I list the unpaid charges AND the $50 service fee and require them to pay the entire amount or I proceed with eviction.

Should I contact the insurance company?

If there are underground tanks or other potential environmental hazards, it gets passed onto an environmental hazard insurance company and they either insure it or they don't. 

Jeff,You should review the Insurance coverage for the property to make sure the Named Insured matches the entity on the title. 

Does this cover your payment with taxes . insurance, and a little for repairs? 

Think of their fee as extra insurance that the deal will close. 

When I tried to get the bank to let us pay for and get insurance on the property, they sent me an acceleration letter.

Make sure you carry proper insurance if it is being run as a group home.

(Government qualifications requirement)The so-called "stress test" determines the borrowers ability to qualify as follows.If  the mortgage loan is to be insured, the borrower must qualify at the higher interest rate of either:the Bank of Canada’s conventional five-year mortgage rate (presently 5.34%)the interest rate you negotiate with your lenderIf the mortgage loan is uninsured, the borrower must qualify at the higher interest rate of either:the Bank of Canada’s conventional five-year mortgage ratethe interest rate you negotiate with your lender plus 2%Regardless, interest rates are still considerably below their historic range of 7-9%.

The longer the gap in insurance coverage, the higher the future insurance premium.