Not having your own currency (especially a crypocurrancy - where it's essentially dividable to millionth or billionth) is not a death sentence to an economy. The U.S. didn't have direct control over its currency until the early 1900's. And once they got direct control, it caused the great depression.

A treasury can offer bonds and control the amount of liquidity in a market. It's not direct control, but all countries used to not have direct control over their currency and they managed (used to trade in gold/silver by weight).

Finally, there are places - such as China which literally peg their currency to other countries. They don't have control either (at least until it's unpegged).

I do agree with you on the traceability, but you can limit traceability via crypocurrancies. Given the pirate party is probably more interested in less government control, they might be willing to compromise traceability for lack of government control