So vacancy to me seems to just be another terminology for all expenses you are paying out of pocket when you don't have someone else covering for them.You have and incorrect definition. 

If so, then what you could do is put in the lease that if the water bill goes over $XXX.00, they have to pay the difference.My concern about the hookups, is that the tenants may put in a unit incorrectly, or buy something cheap that leaks.  

If it is incorrect, please notify me at such and such contact info, by such and such date, otherwise I will assume it is correct."

This is factually incorrect.

I'm going of memory here, and that can't always be trusted haha  Just a quick follow up since I don't want to float out any incorrect info.

I don't know where the incorrect number came from, but everything else on the PDF was accurate.

they are incorrect on their view of essential services.  

The new landlord will do a better job screening.That could be an incorrect assumption, because the current landlord is probably experienced and in many cases the new landlord is inexperienced.

I attribute this mostly to not purchasing correctly while calculating expenses incorrectly from the start, but that's a topic for another discussion.

It’s not worth the risk/liability of your tenant, or someone else, getting hurt if it were to be installed incorrectly.