>>29
Bitcoins aren't anonymous. Transactions can be traced.
They're pseudonymous as long as you don't connect them to the outside world. They can be anonymized, the same way you can anonymize internet traffic (onion routing, mixing, pools) and there are multiple implementations of this (since bitcoing is easy to automate).
Anarchy cannot work with population sizes larger than Dunbar's number.
Depends on what kind. I don't think it's very sustainable/stable in our current state of existence (physical human beings), but it might be inevitable 50+ years if we finally fix some of our issues (substrate independent minds would be ideal (coercing becomes impossible, everyone is easily backed up/can't be killed = laws are no longer enforceable/only software/hardware "laws" are (same as physical law), only mutually beneficial contracts would work), but molecular nanotechnology gets you there quite as easily, just not as pleasantly (people can still do nasty things to each other, but since it would be postscarcity, the need for centralization decreases considerably up to the point where it's no longer needed, however I still expect people to form groups where beneficial)).