I installed a complete system in a 1000 sqft ranch rental but I also upgraded the panel to 100amps & ran all new 10ga wiring & 240V double-pole 30amp circuit breakers to branches of the units in series. 

I would have to have an electrician provide a new circuit for either of these installs.Based on your experiences which option would you recommend?

-----------------------------------------------------------Not at all, as a seller, I'd just say that I'm short-circuiting the process.

I just would like to follow up on original property...I believe there's a septic system issue that is a deal breaker at the current asking....I always keep options open though and maybe a deal for the right price.Axel , exactly my thoughts as well, very good points.Very Good info John , Thanks

Like others I will focus on bids on plumbing, electric wiring, fire protection circuit board, safety, railing. 

However, the property has been robbed of the copper in the house (this includes the breaker box, some piping, and the electrical meters outside).

None of this is a deal breaker but things will need to be corrected immediately following the closing.Thanks!  

These are simple things like check the breakers, make sure the remote is set correctly etc ;)

Called several electricians to do a service change at my house (add a meter and separate basement and first floor circuits) - a job that requires pulling a permit with DOB.Each time I ask for proof of license, electrician says something like "We sign contracts, You give deposit, I pull permit" and doesn't address license.This has happened to me 3 or 4 times.How are these electricians pulling permits if they are unlicensed?

I would place the utilities online then just close off the master water into the home and flip breaker off until you need it.