My cats both have all their claws and two of my mom's do. No furniture has been damaged by any of the cats. Cats can be trained. But really we didn't even have to train ours not to scratch furniture.
The only thing u have to watch for is that cats do have a "preference" for how to scratch. When we got Gordon he would scratch the carpet even though we have several vertical scratching posts. We bought some flat floor scratching posts and now he only scratches those. Just put catnip and treats on the scratching posts and make a loud sound when u catch them scratching something they shouldn't.