So the latest design hasn’t even been made at ponoko… and I already see it is flawed. I decided to restart from the beginning… now that I have a digital caliper, and understand sketchup better. Here is the latest:
I’m not rounding the corners till the end, because it’s easier to edit with square corners. Also, I’m keeping the the panels themselves 2D, easier to work with.
Prometheus Fusion Perfection 
Also if doing the thickness thing is a chore in sketchup you can hand edit the G codes. It is not hard.