Should I (Gasp!) declaw my kitten?

I have 3 month old kitten that I rescued from my husband’s farm (poor thing was near death). He’s been with us for 2 months now, and there is a bad habit that he has had since we got him. He doesn’t touch our furniture, but he loves to scratch at the walls! Even though I carefully clip his nails, he has done so much damage that there are a few areas where we have put up a piece of plywood over a hole that he has made! We do what we can to deter him (distractions, water squirt, etc.) but nothing works. We bought him a scratching post, put catnip on it, and put it near places he scratches, and none of that works (I have come to notice that catnip does nothing for him anyways). We have tried the Soft Paws on his nails, but he hates them. He bites them off and eats them. I don’t want him to get declawed because it’s inhumane, and on top of that, he needs them to compensate for his missing leg (though, he never climbs or jumps). I’m in college and my husband works, so we cannot watch 24/7, and I don’t want to confine him in any way.
I tried Yahoo answers (asking this question), and all I got was criticism for even thinking about getting him declawed. I don’t want to declaw him, but he’s been the most destructive cat I’ve ever had (and none of the other’s I had ever got declawed). I live in America, so I figure a vet won’t help me in this ( they haven’t helped much with other problems with past cats). So please, just give me an opinion, not criticism.
He’s a good little guy otherwise. Other than the wall clawing, he’s a normal 3 month old kitten. I have thought through reasons that he may be doing this, but I can conclude it’s an inborn behavioural problem. He never runs outside when the door is open (he’s knows it’s dangerous out there with what happened to his leg). My husband’s mom has pointed out where other farm cats scratch on the outside of their house, so he may have learned it. But if he did, why is it getting worse, even though I’m doing all I can to deter the behaviour. As he’s getting older, I’ve noticed he does it more, and for longer periods of time. I don’t want to get rid of him (The nearest no kill shelter is 400 miles away, and other than that, he will die on the farm because the other cats beat up on him and he will be euthanized at an animal shelter because they don’t adopt out deformed animals). I’m too attached to get rid of him, but we have to replace entire walls, and put new insulation in, and even fix a few electrical things because of his antics. This isn’t a new couch (which he doesn’t touch, but would be better than this), but new walls!