Unlike others here I'm gonna have a go at addressing your concerns and help reason this out.
Your fear, as I understand it, is that because there is no authority to regulate the value of Bitcoin, then it will catastrophically fail one day when natural market forces suddenly swing into a bank run when some individual, agent, company, etc. sells en-masse huge numbers of coins or commits some action that panics the market and there's a massive incentive to bail out of Bitcoin. Your other posts say that you are confident that cryptographically and procedurally Bitcoin is not in danger, simply that the value of Bitcoin is not controlled by an overseeing agency. OK? ok.
Something you distinguish as critical defining qualities of the USD and BTC is:
- USD value is regulated by the Federal Reserve.
- BTC value is not regulated and only subject to market forces.
On the surface that looks to be a big difference but consider a further, fundamentally defining attribute.
- Federal Reserve can create infinite credit to introduce more USD and impose "interest rates" to mitigate credit created.
- Bitcoin has a limited supply, and fixed distribution rate. No credit.
Now, as I understand it, the Federal Reserve's purpose was to help stabilise massive economies and help prevent catastrophic crashes by creating credit to ease huge losses (essentially bail out banks) and impose interest rates in the good times to help mitigate credit introduced into the financial system (this is obviously a very simple description, and I could be wrong). The Federal reserve's initial purpose was to regulate the supply of money created by banks so inflation didn't destroy the currency, but also soften the impact of crashes in the future (I think this is why in 1907 after the crash the fed was created
https://en.wikipedia.org/wiki/Federal_reserve).
Now if you noticed, USD has absolutely no distribution control, credit into the system and interest rates is largely controlled by the Fed at the whim of men in skyscrapers wearing expensive suits that are corruptible, flawed and terrifying. Bitcoin on the other hand doesn't need a central authority controlling distribution because it is already mandated how new money is created and a HARD limit on the maximum amount of money circulating in the system is very tightly controlled. Everyone that uses Bitcoin agrees to this, without exception or reservation.
What this leaves us with is the market itself. In a USD market swings in growth or a contraction in growth can be artificially slowed by the Fed. But this is also ripe for abuse, wars can be quickly funded by creating more money, as well as bailing out institutions "too big to fail", without needing to hold anyone to account. It means bad men can be kept in power and no-one will necessarily be held to account. Manipulating the money supply to small degrees doesn't adversely affect rich individuals, governments, or corporations very badly but it means the buying power of middle class and lower class is severely undercut as inflation slowly undermines the value of what little dollars they have (this means the rich stay rich since they have a huge supply of money on hand, but the middle/lower class get hit much harder financially, since they have little/nothing for when bad times arise) . Interest rates also hit the middle and lower classes the worst too. Whats more, Democratic systems can't change monetary policy since the Fed is an independent non-governmental entity.
The Bitcoin market however is a wily and uncontrolled beast as you imply. I believe the answer is a bit more grey though. In the early stages of the Bitcoin economy (like now) we will definitely have fluctuations in value that are largely beyond control, it is Bitcoin's wild west we are experiencing right now. Caveat emptor should be the catch-cry for Bitcoin novices. But the fact is that very few people have Bitcoins, the distribution is not thin enough that a single individual's buying power won't cause massive swings as large buys and sells are made. But over time as Bitcoins get distributed among more users, the Bitcoin supply slows, more businesses trade in Bitcoin, and more miners enter the race to validate blocks, I believe we'll see the value of Bitcoin reach a stable level. Bitcoinica also demonstrated how trading mechanisms can help minimise trader's fears and help stabilise Bitcoin value, lets hope another, better implemented and planned trading platform fills this gap. Bad news, and mad rushes as a new part of society embraces Bitcoin as the next big thing are definitely growing pains that we will all experience to a greater or lesser extent. An overseer could "stabilise" this, but we must weigh up the good with the bad here. Any human intervention on value is entirely corruptible, regardless of what "safety mechanisms" are put in place. The USD's Fed system is probably the worst of them all, and I for one would never want a Fed-like system, or even something similar with human(s) at the helm "Benevolently" keeping our Bitcoin's value safe. As long as Bitcoin remains useful, stable (code-wise and cryptographically wise), and well supported by the mining community, Bitcoin's value as a currency is fairly well assured. It needs no overseer.
Trust the market, or trust the Fed. Only one of these has no agenda over the value of your money.