Re: A matter of scale
And this is why price increases for Bitcoin are a good thing. Note the number of Bitcoin is not what measures the size of the currency, rather it's market cap (number times value of 1 Bitcoin). Though for Bill Gates to buy all of them, that would itself cause the price to rocket (especially if people knew that Bill Gates was on a mission to buy all of them). But yes, a bigger market cap means it's harder for anyone to influence the price.
"You can't base your long-term wealth on an asset who's value can drop like a rock from one year to the next."
Oh, good thing that no one's suggesting that today.
Your last paragraph is a straw man, who says you should bet your house, salary and pension on it? I wouldn't trust those things with Paypal, or bet them all on high risk investments. That doesn't mean that those things are of no use at all.