Re: The H.Q.
I love almost everything about this design. The cartoon is fantastic, all the planning and placement is great. I do have one large critique though.
I feel that your use of orange is poor. Instead of using the orange to have such an overwhelming effect in the background, I think it could have been much better used to highlight the details, as you did in the testubes, mouths, pipes, ect.
In my opinion, placing it in the background really dwarfs the image and takes away from the great design. Also, the way you created an uneven border around the design between the outlines and the orange looks like you were coloring with a marker too big for the small areas.
I'd vote for this design in a heartbeat if the background were more visually pleasing, but as it is right now, I would not want my shirts shipped in it.