Don't you worry mate. I've done so, so so much worse then that
. You've done pretty good so far, you'd be proud of it. Some not even know the default "xbox-xbox" thing. The other settings are correct. Are you using a router or crossed-cords to connect your PC to your Xbox?.
Since we are at this, there's one thing that I always wanted to do... it's easy to send files from a PC to an Xbox using an FTP client. However, I always wanted to know how to access files from an Xbox to a PC. I have some movies in my PC that I'd love to access them from the Xbox, for example. If someone finds out how to do it, please let me know