"No central authority" ? Well, I think the guys who decide there will only be 21 million bitcoins can be considered a central authority.
Currency, in any form, is deemed to have a central authority -- national currencies, for example, have real-life value because states limit the available quantity. In this case, the Bitcoins people are acting as the central bank. Especially when I see that the total produced bitcoins will be halved each year by decision.
Someone proposed 21 million coins, and others, by voluntarily choosing to run the software, agreed to the 21 million coin limit. That's not a central authority...just an agreement between individuals.
In all of your statements you're conflating a protocol, and voluntary social agreement, with a central authority.
Anyone is free to fork the software and change the rules to create their own protocol for people to use! If they like the rules, they join...if they don't like the rules, they don't join. Freedom.
