As to who "owns" the KHs, assembly halls, etc., in the US, a religious non-profit does not "own" property but administers the funds and property. No individual owns it either, whether in the head organization or the local organization. Trustees (3 elders) from the congregation in which the KH and property is in, administer local requirements as to title and taxes. The WTS as the parent non-profit only can at their discretion dissolve any congregation and dispose of funds and properties putting it back into the main funds.
As far as the utilities, I have never know the WTS to pay them then reimburse the congregation. The congregation is responsible for paying these bills in a timely fashion. If 2 or more share the same building, a maintenance committee is formed with an elder from each congregation serving as the "maintenace" overseer and coordinating how the utility bills will be paid. Using split evenly, but sometimes a smaller congregation (Spanish for example) may pay less or not at all at the discretion of the other congregation(s).
The WTS still has to approve all remodeling and building of new KHs. Of course, basic maintenance does not fall under that.
I only know what my husband says he knows from his years as an accounts servant.
Hopefully, someone else will simplify the info in the documents Atlantis has provided. The legalese is so complicated I wonder how any elder could decipher it.