In the meantime the tenant could flip the switch to reset the furnace when it shut off and I provided an electric room heater. 

The main heater (gas) was shut off and the gas meter pulled until the furnace can be replaced which cannot happen until  the cleaning is done and joists repaired ect..

Go by their tax returns and if they're way off from what they declare, ask for bank statements for the last year. 2 years is overboard to me but 2-3 months can be a fluke at a new restaurant and they might get fired from there after the holidays.  

There is a grocery store nearby, a Dollar General, and a couple restaurants and fast food places within 1/4 mile.In the area (the other side of the park) they are getting $750 for a 2/br single wide and it is common to see $200/$250 a month for lot rent.  

You can represent yourself in small claims court and this seem like an open and shut case.

Refrigerator ice makers, dishwasher, microwave, garbage disposal, etc.Windows - open and shut them to make sure they work properly.

Are buildings and businesses shutting down?

It shut all lending completely down.

During the winter, I parked my home behind a restaurant where I was employed as a server.

Starbucks, coffee shops, bars, breweries, and trendy restaurants.