I buy property from the 1880-1920 all the time and don't have to deal with anything other than brining them up to modern code...but in my locale, that's only required if you start doing work...ie if I don't touch the electrical I don't have to worry about upgrading it, but as soon as I touch it...BAM!

There were issues with termites, the electric was really not up to code, the HVAC was complete trash, there was mold, and the inspector had doubts about the health of the roof because he couldn't get into the attic to inspect it because it had been sealed off apparently for who knows what reason.

He does plumbing, electrical and carpentry.

Also in my county if it has been vacant for more than a year power is disconnected at the main, in order to get it turned back on electrical must be updated.

I think the last one we did on a new build (2012) was >$1500 with the tank plus the ancillary costs of plumbing & electrical hookups. 

The Air conditioning wasn't turned on before she came in and it was too hot (tried saving electricity no one in home). 

I train contractors in the HVAC, Plumbing and Electrical industries.  

It sounds like you haven't spent much time working in an electrical panel, so I'm not sure I'd recommend this as a first project.

LVT Plank for floors etc in the future (also recessed lights)Basement: Cleaned out, updated electrical, plumbing, and GAS (used to be oil) with new central HVAC unit installed and ready for hookup to the PGW line (waiting on PGW). 

You'd have to be able to convince tenants that the higher rent you're charging (compared to the local competition) is worth it because the tenants will save money on their electricity bill each month.