The house was built in 1958 with original electric, 2 prong receptacles throughout the house, no A/C unit, original plumbing (copper and cast iron), original bathrooms and original kitchen.

Treat with Termidor on the outside perimeter.On the inside, treat with Phantom, around pluming drain and supply protrusions, window sills, behind electrical plates, door thresholds.Phantom: http://www.amazon.com/Phantom-Termiticide-Insectic...Termidor: http://www.amazon.com/Termidor-SC-Termiticide-20-o...This one two punch is very effective.

I have a strong background in construction, including electrical work.

Same applies in REI, IMO.I'll go right to step two and say appreciate the power of leverage and protect your credit. 

It says it has upgraded plumbing, water heaters, and electrical.  

I just installed a new central AC system at a rental unit.The install cost me over $3500, and Florida Power and Light offers a pitiful $91 rebate.I heard in some other states the power companies offer a significant rebates to a new AC or furnace, or even energy saving appliances.Anyway in order to get this $91 rebate my AC installer asked me to provide to him the FPL account number of my tenant living there.When I asked the tenant about the account number they questioned whether that rebate should be going to them or me.I paid for the central AC system.Yet FPL is offering a rebate and requested an account number for the rebate, giving them an impression this is the account which should be reaping the benefits.What say you? 

Tenants pay electric, gas, heat.

Electricity shouldn't be a problem but it may not be realistic to separate the heating systems.

He hired a guy he knew for the electric and signed a contract with him, then gave him one of our checks for $1000 as a down-payment. 

Is this off grid (some banks won't finance homes with no power).