21 million for an entire global economy is ludicrously low to begin with when you think long term and large scale. Imagine trying to operate in an economy where a single penny will buy you an air craft carrier. You'd need the intellectual equivalent of a clean room and an electron microscope just to buy a pack of gum.
Complete nonsense. The supply doesn't matter when you can divide forever. Even 1 BTC is enough to run the whole economy. It's just a fucking integer, for Eris' sake.
Also, please reframe from making such a gigantic post.