They don't want a pile of "buyers" in and around the property disturbing tenants while its on the market4.

What, your lease does not require the occupants to sleep in the bathrooms (???)

Guest Policy - Because this house is created to provide a place to work, eat, and sleep, and because of the size of the house, tenants are not allowed to have guests visit or stay at this property.2.

Better news, you can sleep at night not worrying that a bunch of late 1990's era water heaters might fail and fill your place with water.

Most of us have leases that prohibit disturbing the neighbors - or having a civil or criminal action taken against the property due to misconduct.I do recommend getting involved at this point as it is doubtful that any future tenant would encounter something different than your current one. 

In fact, you should have done it when it first happened.Even if he is mentally ill, he doesn't have the right to disturb the neighbors and you have a responsibility to protect the right to quiet enjoyment for all your renters.Give him a written warning that if this happens again, you will terminate his lease.

I can really only afford to take on the costs of the bottom parcel without losing sleep.

I also find I can rent my place within a few weeks so I don't lose sleep if someone needs some time to decide on an extension.

That doesn't look all that bad, I wouldn't lose any sleep over it.

If you’re bing disturbed you don’t really care what’s causing it.