+1 for the first and second points, but I think it will play out much differently.

Facebook will try to defy regulators, but I think the SEC will stomp on them, hard. It will end up a hybrid battle in the courts and Congress between libertarians, a few flavors of privacy advocates, US regulatory concerns, and ultimately land on US power projection concerns.

I think the US will eventually shape the law and regulatory environment to prevent the existence of any cryptocurrency with its own valuation - distributed ledgers denominated in central bank currencies will be all that is allowed at the end.

The US financial system is a core pillar of US world power and Congress isn't going to give that power away to Facebook. It will be a complex road because the issues are difficult to grok.