2) "Invest your bitcoins in something more volatile" is only an argument for BTC if those more volatile assets can't be easily traded directly for national currency.
Hm..if you buy something like Asic Shares PTs, selling and withdrawing the Btc doesn't take that long. So if we see more like this, there shouldn't be a problem.
3) Being less attractive to speculators isn't necessarily a bad thing if it means you'll be more attractive to businesses.
True, I'm just saying you can have both ^^
A stable Btc price and an investor playing field within the Btc.