A few months later a different sales guy started hitting me up, and I again explained what I was looking for and that LM likely wouldn't fit the bill. 

My options are:-Refinance now and foot the extra bill and stay in this current home (I would be footing all future closing costs) and pour most of the money earned from the other sold home into the one I currently live in. 

Quote from @Bill Hampton: @Alex ShowWelcome to Bigger Pockets.

I know in New Jersey, you cannot bill if you clean it yourself outside of the actual chemicals used (I.E. free labor).  

Now all of a sudden you have these new cabin units and you can significantly reduce your tax bill at least in the near term by splitting out the components.

My name is on all the bills so they get paid.

It can boil down to human error and things we can control, but sometimes it is just an issue out of everyone's control. 

Equally Splitting the Bill: One straightforward approach could be to divide the total water bill evenly between the two units each month.

Utility bills can increase significantly if guests stay for months during hot summers or cold winters.

In most municipalities approvals have a few year shelf life and in the event new regulations or new zoning bills are passed you could lose the benefit of the in place zoning/development procedures.