Isn't it the case that with low (even if stable) prices, any large transaction in an exchange will move the market, thus causing volatility?
I believe so.
The only way to a more stable and functional market is increase in "market cap" (a misnomer) - and since supply is set in stone, this means increase in exchange rates (influx of fiat capital).
I agree. To some extent, the price of a bitcoin is a measure of the success of bitcoins. (Though indirectly.)