That makes no sense, of course they can, they can raise interest rates which decreases the supply of money. The thing is that would hurt the economy and their goal is to maximize employment.
They can not, because the enormous amount of money that they printed the last 10 years is not in circulation yet. They can't simply take that back (only very indirectly through ways that are both illegal and would political suicide). The private banks who hold that money now decide when to put it into circulation; the central bank has no power here.
Sure, but right now unemployment is under 4% (pretty much at record low levels) while inflation is running hot at 8.5%. Seems like they've got some room on the employment side.