A switch is just breaking a circuit.  ____/  ____ is off and __________ is on. 

For the electrical we had to call PG&E to come out an unlock the breaker box so we could change a main breaker just to run our inspection on the houses electricity.

As an investor I wont pretend to be an expert in everything, like for example if I need to install some new fixtures I can get my ladder or step stool and knock that out with no problem, but if I need to rewire a circuit breaker or get an old house up to code I will call an electrician.  

(40, 60, 100, 200, 400 amp) Fuses or circuit breakers?

With lower priced property's (sub 40k) with good cash flow and COC, would a 17% vacancy rate be a deal breaker?

If this is a deal maker or breaker I would not only get an answer but I would have them direct me to where I could find this in writing.

There are breakers placed in to prevent a major drop/panic.  

Do these two things seem like a deal-breaker to anybody?

From my experience I could tell you what kind of tenants you'd likely get given the area and price-point, what units you're competing with locally, what kind of layouts are preferred, what kind of amenities are preferred, and most importantly, if any "deal-breakers" exist in the unit.

.- I have a duplex that didn't have separate meters for Electric, so I added a separate meter on one side of the duplex near the breaker panel for that duplex and then take a reading for that unit each month.