No, while velocity is relative, acceleration is absolute. An accelerometer does not need any reference point. Well, it cannot tell the difference between acceleration and gravity, but that's an other issue.

That's actually not the case. You can tell whether you're in an accelerating frame of reference (like a car stopping) or an inertial frame of reference (like a car cruising) by the forces you feel, so they're not really co-equal.

Obviously there are problems with metaphors but my point is that to say the dollar is volatile in the OPs example, he needs to say that all non-Bitcoin currencies are volatile.

From the position of relative perspective that may be a valid theory, however in it's not the one best explains what is being observed.

bitcoin theory of relativity...