This is a total contradiction: You say you discourage hoarding, but give interest on .. hoarding???
If you give interest on a coin, the only thing people want to do with this coin is hoard.
I kind of already asked this 1 page ago, and the answer is still kind of strange. It has to do more with balanced mining and getting rid of the hashpower monoplies, according to the response. Mining is only a small portion of hoarding though, so they should really stop advertising that..