#3 is AWESOME!! Wish we had space for something like that!
(My husband and I once saw a tv thing about a couple that had turned their whole house into a big rumpus room for their cats. They had “ladders” up the walls, shelves all the way around the top of the rooms so cats could walk around, actual holes cut in the walls between rooms so the cats could go between ... and we sat there and seriously thought about doing the same thing to our house! LOL!)
Also plead guilty to #4. Some things are worth more than money. :o)
#3 is a tempter, isn’t it?
I had a friend tell me the other day that she and her significant other had done some stuff like that. They have little shelves and pathways on the walls for their kittys.