So, assuming you didn't get out of college in December, and that you've had some appreciation, you can probably end up neutral with a lower payment.

We have borrowed a total of $50k to make it cash flow neutral (in terms of the investment, not in terms of monthly cash flow).

This season we rented to the same couple for the 3rd year and received $2400 per month, and we stayed in it 10-15/1-15.We decided to consolidate 3 homes to buy and move to The Villages, FL (most fantastic place for retirees on earth, period.We got in the 50's when we sold AZ in Jan so really had a 12 year cash flow neutral situation with lots of great free fun and memories.there are a lot of people buying here in the Villages and using as rentals.

You should check all the neutral wires on the bus bar to make sure they are tight, as that is common.

No main grounding through a rod is present with the age of this system (meter jumper cut is a potential hazard), neutrals/grounds bonded in 1 subpanel is no longer approved.

For the latter you can often find quite a few nice neutrals. 

Your original goal sounded more like a long-term play that's neutral for cash flow, but with a good chance of appreciation & the tenants covering all your expenses.

This would help you get closer to a neutral position with the rent covering the note.

It is not in bad shape, just outdated, so in order to get max price I would put in some of the basics (nicer kitchen and bath, nice neutral paint, new carpet or laminate, fireplace mantle etc etc).

Almost sounds like that receptacle in the other room has the neutral fed by the "load" or "slave" output from the GFCI, but the hot comes from the "line" side of the GFCI.