Yes, it’s short for “cooperative”. All of “coop”, “co-op”, and “coöp” are all technically correct (historically cooperative was spelled coöperative and co-operative), but co-op is probably the best to use because “coop” usually refers to chicken coops.

Ah, I see. So being “devalued” is like mixing base metals in your gold coins, while “cheap money” is like loaning out the treasury. Both contribute to inflation, but in different ways.