The electric bill came in kinda sudden last month1.

Would you need to add/extend plumbing lines / change the electrical panel for the dryer voltage.

You are also in the northeast which is crazy expensive to heat, especially if using electric heat.

To switch from the Electric trucks to petroleum based trucks.

Seems that the tank was "rented" and owned by the propane company and they wanted their tank back.We have also switched many properties from oil heat or electric heat to more economical natural gas. 

My concern is there are window AC units which could result in much higher electric bills in the summer. 

Upcharge for spa boxes, maybe a massage or concierge services, etc...Those marketing strategies will boost your bookings and top line revenue, plus make you more memorable. 

With this, I could essentially charge a flat rate for electric to the units.

Mostly small things, biggest things have been a new electric panel, appliances for one unit, fresh paint for one unit, new garage doors.

Some of the things that have happened during the last 7 years of running STRS, loose deck boards, rotten outdoor steps, broken interior hand rail mounts, loose electrical outlet...Any of those could cause a major accident so they were repaired asap.