On the op's question about finding ways to discourage hoarding: It's unnecessary because these incentives are self regulating. I also agree with other poster's takes on the word "hoarding", a negative connotation for "saving", which is actually vital to growth and investment, but for the sake of argument lets work under the assumption that it is actually bad.
"Hoarding" only pushes up the value of bitcoins remaining in circulation, as well as the demand for bitcoins. At some point a hoarder will sell bitcoins or buy goods when he feels the value of the bitcoin has risen to his expected level. Hoarding for the sake of hoarding has no value whatsoever, because bitcoins themselves have no utility by themselves, only as a tool to facilitate transactions. So yes a hoarder could change the value of coins, but the value fluctuations are necessary to create incentives to spend or save.
Eventually as the economy grows, i see the value stabilizing, but right now things seem very volatile since the only real utility is speculation.