Well, being subject to S&D of money is why they have the mandate to keep inflation at 2%, no? You can argue that measuring inflation is a poor way, but you'd have to come up with a better alternative.
No. In Friedman's "Monetary History of the United States" he shows how the Fed setting interest rates was rather erratic and much more unstable than the earlier free market mechanism. The Fed would guess at what the S+D point was, since the Fed was not subject to market forces. This meant they were always late and always wrong.