.; how to analyze properties, how to engage in a strong due diligence process, how to screen tenants, how to manage the property, how to build a network of contractors, plumbers, electricians and other pros, how to manage the book keeping of the property, etc., etc., etc.

Get a electrician to see if your existing panel has the capacity to service this new space; if not you may need to get a sub-panel installed. 

Unless he is a licensed plumber, electrician and has experience with cabinets, I feel like this is a disaster waiting to happen.    

Zoning department, engineering, plumbers, electricians, hvac, attorneys, etc.  

Instead of using a GC, hire a plumber, electrician, window guy, roof guy, etc.

If you haven't already done so, then you probably want to have an electrician and a structural engineer inspect the property to evaluate any further issues that you might encounter. 

Within hours of getting the keys, we quickly went to work painting the units, replacing older appliances and hiring a plumber and electrician for some minor repairs.

Quote from @Cliff Benner:I would like the target Military and Medical in the area I am looking at.Try welders, fitters, boilermakers, electricians and inspectors. 

Gas sub metering would be an electrician job correct? 

Welders, fitters, boilermakers, electricians and other such ruffians.