Anyone that offers you a "one size fits all, silver bullet" solution is just trying to sell you something.

@Kody Veit If you are in the house, hacking the deal on your own, this is your deal and you have no time or energy for anything else coming at you. 

Pros for real estate:1- Depreciation would allow you to offset taxes thus increasing your net.2- leveraging increases your cash on cash returns.Pros for a passive investment:1- it will take less time and energy.

But at this point i'm focusing my energy on choosing the best possible contractor (and it has not been easy!). 

I think youre missing the point here.I asked about heating small APT with an ELECTRIC tankless water heater since it uses less energy to heat WARMER water, in other words if incoming water was 120 and return was 130 only 10 degrees not much energy needed to bring water to additional 10 degree.propane is expensive todays rate 2.20$ a gal summer was 1.80$ gal using a tankless GAS water heater min 150k btu propane uses 90k per 1 galon so that 150k boiler costing you $1.60 an hour of operation .

Nothing sexy about these at all except that they're about as bullet proof as you can get in this market.

To add to @Shawn Clark point... there’s supposed to be a high speed DC-Baltimore train coming (who knows when) that’ll take you from city to city in 15 minutes: https://www.google.com/amp/s/dc.curbed.com/platform/amp/2017/10/16/16482438/dc-baltimore-bullet-train-shinkansenI️ have a rental in Baltimore that I’ve seen great cash flow with and I’m looking for more.

Otherwise, you might have to bite the bullet and pay for bookkeeping services.

There's no right or wrong answer, but I'd encourage you to really nail down your priorities re: time, energy, engagement, and returns.

On the other end of the spectrum, you find the {near}vacant building, buy it for nearly nothing, and give it a deep retrofit (energy efficiency improvements, layout improvements, update core systems, and refinish throughout).