Otherwise, there is nothing preventing your tenant from taking daily hour long showers, inviting people over to do their laundry, etc.   

Highest and best use is likely patching up this 100-year old building and maximizing cash flow (add on-site laundry?)

Is it just by the cleaning bill from washing the walls with tsp when they move out?

My highest rent is 1400 for a 3 br multi level apartment.Features new hardwoodfloors and SS appliances.I spent alot (probably more than I should have) on updates to common areas such as laundry room to make overall house more confortable for my tenants so I feel that charging on the higher end for rent is justified.

For example, coin-operated laundry, renting a garage or parking space, Airbnbing your unit or getting roommates. 

Common electric runs $231/$155 month winter/summer (common laundry has an electric dryer) but all apts pay their own electric. 

lol.They're claiming the septic didn't work (found to be a clog in the sink drain by my plumber), the laundry facilities didn't work and they couldn't launder their clothes (drain and electrical outlet were repaired and I never heard of a problem after), they said the refrigerator stopped working so they had to buy their own (which I was never contacted about if this is the case).  

The most prominent problems that I can think of are:Booking/screeningCleaning/laundry/turnoverHandyman on-call for repairsAnswering questions from guestsYou can set up autoresponders to handle booking/check-in/check-out and even requesting reviews/feedback.

Use the proceeds from the cash out refinance to pay off your HELOC, wash, rinse, repeat.

They had it setup so that both halves had independent everything except laundry which was shared access on sort of a landing in middle of the two halves.