I have some electric heaters I drop by if the heat goes out in winter (before night).

I would bug him with a phone call for every little question that I had.

Better if new construction with exposed drywall, like most other mechanical and electrical systems.

Tell them not to paint the electrical switch plates and no dark or bright colors.

Have some electrical tape ready and additional wire nuts, the ones supplied almost always are trash.

Is anyone using bed bug spray on their mattresses after a guest checks out?

I initially had 1 vacant unit and had to cover the gas/electricity for 2 months.

While doing the repairs to the legalize the basement unit, you may have to do other work in the building like upgrading electrical and water service etc.

Where did he get it I am picturing a guy standing on a corner with electric meters in a trench coat. 

that's some pretty high space rent for a small park with old mobile homes.. were is that. you have major cap ex you have to save for .. since you have to keep the water sewere electric storm and all those systems functional long term.. unless everything underground is brand new. 50% running costs is realistic 15% no way.