Everything you've posted is contradictory. You say you know declawing is bad. You say you are against declawing. You say know it's a painful procedure... but still you're gonna do it anyway.
Also, your main excuses to do it are:
1. My mommy won't let me have a cat unless I mutilate it, and I want one so bad I'll do anything to get one. - yea, that sounds like you're mature enough to own and care for an animal
and:
2. If I don't do it somebody else will anyway.

In life, we have two choices: Be a part of the problem or a part of the solution. I guess we can see which part you've chosen.