This looks great and i will be a customer for sure.
Personaly I am not a fan of limited run T-shirts, they never fit me right so i tend just to wear them around the house and dont get to show em off. And collectors [special] T-shirts i tend not to wear because unless they are very very high quality they fade etc. So again they tend to stay in the packet and not get worn.
Mugs on the other hand I like - i take em to work etc and get to show em off and get asked about em etc.
Badges I like too.
Hope this helps - the whole idea is great