6 points for creativity and general appearance of the final product. Add another point for the delightful nerd-a-rama discussion it evoked. Priceless! By the way, take the man's diagrams. They could only help you make even better future models.
By that logic it would be okey to have square wheels on a fantasy chariot. after all, it's "pretend". *ROLLEYES*
Cool idea with the sprue capapult. But I do agree with NSA's comment on functionallity.