Yeah, generally, you have to be doing something for the whole organization. The only person that I know that has Dragon Stamps is Bryan Gregory, who is on the Alliance Rules Committee (the ARC). I don't even think I have any, and I wrote part of the current rulebook. So, net, they're really hard to get.
A Dragon Blanket is exactly like a goblin blanket (AKA a monthly blanket), except that you can have both a Dragon Blanket and a Goblin Blanket on the same character (I think).