Some things, like upgrading the electric service, is kind of a no-brainer that it needs a permit.

Could have electrical issues or potential fire hazards.

They may just have you rip out the sheetrock so they can inspect the framing, electrical and insulation.

Don't forget electrical hook up.

It sounds like you definitely need heat in there, maybe electric baseboard heaters for ease of operation?  

Mitsubishi Electric is going well, but passive income is certainly the better option. 

Does it have easy access to electricity, water, sewer, gas lines etc.  

With a sloped back yard I would be concerned with possible water retention against the house and animals jumping on the roof to get into the house.With the house being older and a renovation did you take pictures of the electrical being replaced and plumbing etc.?

The electrical is outdated.

Understand what is required first, don't some floors go before cabinets are set, some not, don't paint before the electrical guy, he should be one of the last ones out, a carpet layer can be the last guy out.