I am looking for insight and expertise with the HVAC system, because I am newer to real estate investing.There is currently one natural gas furnace in the basement that pushes air to all three units and floors.  

Do you like green nature or water? 

First, you can't terminate the lease until the natural expiration date or until all parties agree.Other than that, I would just write a simple letter explaining your intent.

When catastrophe hits, they naturally can't keep up.

If I need to do a double close and pay the fees I will, I would just prefer to milk this thing as much as possible, naturally. 

@Jennifer Marshall, There are large slabs of both natural and synthetic stone in high end tile shops.

I do NOT recommend you get the seller to fix any issues unless they are very easy and essentially cosmetic in nature.

It was (and still is) nature photography as I would take my camera hiking with me and on vacations.

If you are a micro manager by nature I don't recommend it as you'll need to hand the reigns over to other people. 

Way to hard to clean food and dust off of. example:https://www.homedepot.com/p/MSI-Alaska-Gray-Splitface-12-in-x-12-in-x-10mm-Marble-Mesh-Mounted-Mosaic-Tile-ALGRY-SFIL10MM/206741880Too busyhttps://www.homedepot.com/p/MSI-Magica-12-in-x-12-in-x-6mm-Glass-and-Stone-Mesh-Mounted-Mosaic-Tile-SGLS-MAG6MM/206741857Very uniform and neutral, adds design fare.https://www.homedepot.com/p/MSI-Honeycomb-Hexagon-12-in-x-12-in-x-10mm-Natural-Marble-Mesh-Mounted-Mosaic-Floor-and-Wall-Tile-HONCOM-2HEX/205307895