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This is a tricky topic that most people don't know what to do with. Cats are safer inside than out. Yes they can make it but it's starting to be in their nature to be with people.
So I have a cat that was an outside cat and now she is stickly inside. She does miss the trees and the little things to hunt.
For her hunting I get toys that resemble birds and with feathers so I can keep her intertained. Just a little time out of your day to play with your cat.
As for the climing I make my own tree homes and cat condos. I put boxes along the bottom of my walls. I have bookshelfs and I cut holes in some of the wood so she can climb with in the book shelf and I have shelving up and down my walls so she can climb. I don't damage the walls at all I use the no nail sticky strips to hold up the shelving and it's strong and it's lasted. If I couldn't make something online is cheaper than going to a store. You'll have to shop around. I have 4 happy spoiled inside only cats and they love their room and they feel just as adventurs if not more than outside cats because they are safe and they have freedom.
If you limit your cat (beside like the counter tops and all) you are depriving your cat of what it's true nature is to explore, climb, and play. It will make your cat a bit depressed. It's always best to give the as much play room as you can even if you don't have a lot of floor space they love window sills and they love the climg and cat trees.