People who have done this before: any advice on the layout of the holes? I've attached the DWG I have so far, but the information I have on how things must be aligned is based on lots of random information from various sources on the web. If someone were willing to take a quick look and see if something is obviously not going to work, I'd be very appreciative

For those who are curious about the layout, this is what it looks like:
I used a ruler to align the keycaps on my desk, so I could get a feel for how comfortable it would be.