When you get any pet you need to understand that there is a lot of work involved. If you can't put that work forth than you shouldn't have a pet. Teaching your cat not to claw everything takes work. He/she isn't going to understand immediately what you don't want clawed and what you do. You have to teach them. We have four cats in our house, and although they occasionally find something to claw we would rather they didn't, they only really do it once because we teach them not to. Plus, we have something they can scratch. If you get a cat, and choose not to make or buy something they can scratch than you deserve every clawed up piece of furniture they give you. Don't amputate a digit from your cat because you can't get off your lazy ass. Your laziness and irresponsibility is YOUR problem, not your cats.
2. Your pet is a pet
I am a firm believer that a household pet is family. You wouldn't cut a body part of a family member off just because what they did with it bugged you. If you are prone to such behavior please don't have a pet... or children and seek immediate medical help.
3. I care more about my house than my cat
First of all, you should really research something like declawing before you decide to do it to your cat. If you do, you'd know that it isn't just taking off a nail, it is amputating part of a digit. See here. It is a very painful experience for the cat. What it comes down to is you willingly crippling a creature who has no say in the matter and relies on you because your couch is more important. Once again, don't get a cat. If you would put your STUFF over your companion, a living creature, then don't fuckin' get a cat. I can't stress this enough. Furthermore, if you have a cat or plan on getting one, you have to understand that even if it's not an outdoor cat it will at some point get outside. They are curious and pretty crafty and they will need their claws once they get out. Declawing is taking away a natural defense for cats. You will be rendering your cat unable to protect itself against other cats and animals. But hey what's a few scratches or worse on your cat, at least there aren't any on the furniture.
Now, let it be noted that SOMETIMES declawing is necessary. My sisters cat Seven is a polydactyl, meaning that she has more toes than normal. Unfortunately she also has a problem with her claws growing into the pads of her paws and they also get caught a lot on fabrics when she's trying to walk which hurts her or causes her to fall awkwardly. In-order to help with this my sister has to trim her claws regularly, which she does. Doing this requires two people and is very stressful for Seven. In this case it might be more beneficial for Seven to have her declawed.