The calcium buildup will prematurely wear out the heater(not in your case, ancient heater that runs forever) and allows bacteria growth as well as decreased thermal capacity.

No ancient Romans still lingering around.  

Ancient Mt Range, nothing like Rockies, but yes, we do have that kind of topography in MN.

Keep the balance at zero dollars, pay the $75/year maintenance fee (or whatever the nominal fee is).Reasons:- First and foremost, now that you owe $0 on your primary residence, you can paint the door red in accordance with the ancient Scottish tradition (and BP members everywhere will know you as a heretic for not being mortgaged up to your neck).- You also have liquidity that is the envy of REI everywhere.

They can see bad roofs, worn flooring, ancient furnaces when we tour the house.

That seems far and away the most likely explanation for what people claim has been happening at this point, and something I would most definitely investigate before I started thinking about the necessity of disclosing to guests that your brand-spanking-new cabin is haunted by the same unrest that haunted the old cabin that used to be there because of some ancient event that only could have happened somewhere else.

And my only electric experience is my grandmas’ s ancient one.

The terms landlord and tenant are ancient relics of feudalism, have a lot of negative connotations and I see no reason to hold on to them in the modern vernacular. 

There are just SO many sheep out there that follow the ancient old rules without question!

In traditional (ancient) societies, your income depended on a variety of factors, such as your ability to be successfully violent against others, your ability to protect your land, your connections to the king or other powerful people, etc.