I'm pretty sure I explained the value of use of bitcoins as a medium of exchange in footnote 2. The convenience and ability to facilitate transactions on the black/grey market might cause bitcoins to trade at a slight premium. On the other hand, volatility, concerns over hacking, exchange lag, and the threat of future government regulation may overshadow this and cause them to trade at a slight discount. I split the difference and assume that prices in the bitcoin economy adjust relative to the spot price, so that the real exchange rate is one-to-one. The problem isn't with the utility of a crypo currency in the abstract. It's that this will never come to fruition with built-in flaws like deflation, which inevitably lead to bubbles.

But you seemed to leave out an important component of valuation, unrealized capability. The protocol supports more than has been implemented.

Such as?

I listed two examples, not sure what you're looking for. But, this page has more: https://en.bitcoin.it/wiki/Contracts