You can change around words but it doesn't make it any different. If I bought 100 bitcoins and essentially buried them in my backyard then supply has been reduced. So has circulation. I artificially decreased the supply and circulation to fit my own goals, hence manipulation.
And you paid for the bitcoins. What's your gain? You mean you can hold on to them until the value is higher then spend them at a profit? Now they are back in circulation and you had no cash flow for X amount of time. It's still completely driven by the market. That's the idea. You can do the same thing with dollars, essentially betting the value will rise (or fall), but with dollars now you have to look at a slew of factors, not least of which is some suit somewhere that decides to print more, immediately devaluing your holding. There are currency markets. None of your arguments, which I suspect are based mostly on your familiarity with the dollar and suspicion of something you don't fully understand, change these facts: 1. The bitcoin can not be counterfeited. 2. The bitcoin can not be inflated by sources outside the market. 3. All currencies are simply measurements of energy. 4. All currencies are subject to the faith of their acceptance as a measurement of energy.
As far as your hard drive breaking, I do believe they have a system to account for this built in. The bitcoins however can not be destroyed, so if you lose some, and have no recourse to get it back, you will be out the money. I doubt there is no recourse though. I'd have to check.