If you have single pane windows, in one unit you can likely hear pretty much everything that goes on outside but what that means is that outside people can hear what's going on inside and so it goes.

Tenants can get upset that you are dangling repairs over their head for more rent, but they can not take legal action just because you want to raise the rents (so long as there aren't laws about rent increase limits...)If it was another type of improvement, like double pane windows, that is attractive to all tenants, the answer I think is easier.

I feel that the relationship is strained to a point where he feels it necessary to call me and complain about things that are not hurting the property at all, temporary things like me leaving building materials (old windows) next to the house out of site to the street to haul to the dump in a week or so.

Next, how old are the windows, are they single or double paned?

I know it does not sound much better but trust me the added stress of having a problem tenant in your property and the mental strain is way worse then just having it sit vacant.

If I had some 20-something kid with a pit bull who was straining at its leash and peeing all over the place while we stood there talking, and HE said HIS dog was a service animal, I'd be extremely dubious.

Hello,As I was inspecting a property for which the lease ends soon, my tenants showed me that the inside pane of a big bay window is broken - it isn't just cracked, a part of the glass fell. 

If the many flippers cant finish a project or flip for profit -- HM lenders will try to unload properties  once they foreclose and put additional strain in the marketplace..

If we look at last year's deaths"2019 Flu Season: Up to 19,000 People Have Died; Vaccine Protecting About Half Who Get It" By Ron Brackett February 17 2019 04:34 PM EST weather.com"and compare what we now have 2020 Florida reports 2 dead from coronavirus, first known fatalities on East Coast  By  Caleb Parke | Fox News"The announcement raises the U.S. death toll from the coronavirus strain to at least 16, including 13 in the state of Washington and one in California, with at least 253 confirmed cases across the country."

This one seemed to match pretty well to the above: https://www.overstock.com/Home-Garden/Simple-Living-Antique-White-Frosted-Pane-Wall-Cabinet/6356567/product.html?