They love to perch on the wall and chill there  indefinitely until I smash them into oblivion. 

They left the openings for a double wall oven empty.  

Neither of these seem to be the case.Sorry if this was a wall of text.

Quote from @Jaron Walling: Agreed with comment.

I had a tenant put up a temporary framed wall with sheetrock and they had a door.

Zero art on the walls.

"Reality TV" is not reality in most casesHost:  "Your pipes are shot and leaking and there is mold everywhere in the walls this is TOTALLY going to blow your budget"<comes out of commercial>Owner: "Well after the $125 to re-do the pipes for our entire home and $25 for whole home mold remediation our budget was stretched really tight but I think we can sacrifice the vase in the guest room and still make it"

If I was going to replace with a high efficiency system in the next several years, I definitely would not line the chimneys as they could be vented side wall and not even need a chimney.

This is one is different than the first because the current owner will be retained as the manager for the first year.

I have had to paint a couple of walls once.