Coming from a financia and economics background, I'm always hit with this same question. I'm playing devils advocate here, and would like to see other responses
My big question on Bitcoin is: What happens after 21 million?
Since I know that you have, and will continue to, be hammered by the Austrians in the crowd for echoing this Monetarist theory position, I'm going to address the questions posed about 'price stickiness' and velocity.
Fiat currencies, as they are used today in a functionally digital form (i.e. bank accounts, credit cards, debit cards etc; not cash in hand transactions), all have a maximum velocity that is largely constrained by the settlement period of these payment methods on the one end, and the payday cycle on the other. To illustrate this point, the laborer may be able to spend on credit, but only to a point. Over his lifetime average, he tends to spend paycheck to paycheck, like most people. So he earns his money, and that money cannot (generally) be spent before payday. If he buys something with credit, he has it before payday but the funds are not (practically) available to the vendor until the cc transaction clears; so his velocity cycle is no faster than the 30 day average clearing time for credit cards or the average 7 day clearing time for personal checks. Prices
appear sticky for many reasons, but the max velocity time for the consuming public is one major contributor to that perception. However, it's just a perception.
Of course, cash or bullion used in person have a near instant max velocity, limited mostly by the time & costs of moving physical objects from person to person & marketplace to marketplace. While Bitcoin doesn't have an instant max velocity, since it generally requires a minimum of 6 confirmations for turnover; nor does it suffer from the physical limitations of transportation. Overall, the delays of cash & bullion versus bitcoin are likely a wash; or perhaps even favor bitcoin. (After all, an hour after you pay for your groceries in bitcoin at wal-mart, they could be paying a cashier in Bangladesh with those same coins, and in another hour that same cashier's wife could be buying cloth in another business while her husband is still at work) Therefore, bitcoin doesn't have the constraints on velocity, or economic 'friction' as many here refer to it, as any other secure distance payment option available before bitcoin. The illusion of 'sticky' prices in bitcoin will either not exist, or be a local pricing issue.