[XorNot]

Why, why, would a central bank use the concept of "mining" in a cryptocurrency?

They're a central bank, and they want to be able to control the money supply. All they have to do is generate some suitably strong keys, and use regular PKI infrastructure to verify them and transactions with them.

Which you know, they've done - that's the modern credit card system (though I am open to the idea we could create something at a government level that was lower fee.