I would be careful of to much designing on the forum. It could almost be a guarantee it won't happen do to copyright, trademark issues. It's similar to the rule not to submit photoshop knife designs. If Dan does come out with a t shirt that is similar it could be a legal issue. It's kinda like producers won't read unsolicited scripts because if they make something similar in the future someone will say they stole the idea from them.

I think it's a great idea, but I think the images will kill it before it gets off the ground. Even if you state you are giving the concept to Dan it can cause legal issues Dan doesn't need.