Pennington

Cats need a scratch post. If you get a good one, they will stop chewing on funature almost immediatly. Personally, I've only heard of going outside of the litterbox once, and it was my cat. Turned out he had a uninary tact infection. After we took care of that, he was fine.

I've had 3 cats in my life and none of them have ever been hit physically. Most of the time, positive reinforcement works for me. When one wouldn't stop scratching on a chair, I placed his scratch post next to it and anytime he even looked like he was going to scratch the chair, I picked him up and placed him next to the post. When he started to scratch I would give him a treat and pet him, say good boy ect. For times when this just doesn't work, the water squarter worked for two of my cats. The other only responded to a super soaker pumped up without water. Gave her a bust of air that she hated. Do that immediatly after or during the bad activity and they will soon stop. You have about 5 seconds to punish them or they won't know what they are being punished for.

And make sure that they see you when you feed them. They love the one that feeds them. Yelling out "CATS!!" before you pour the food can make them learn to come when you call, even if it isn't by the food. Just make sure you pet them whenever they do come.

/me is a cat lover

[edit]- a few more:
Never declaw a cat unless its unavoidable. I've never seen a cat get as depressed as when my older sisters cat got declawed.
Cabinate locks are a good thing.
As for going all over the place, just pick them up and put them on the floor anytime they climb onto a bookcase or piano or something like that. usually works. If not, the air/water spray works well. Just make sure you do it fast.