Didn't happen in January 2009. Production costs for the biggest producers are probably close to nothing.
Yes, it did, all kinds of supply was in the process of being mothballed. "Fortunately" prices didn't stay down long, and the process was interrupted.
As a market trader, is it beneficial to be concerned about "who" or "why"? When you come up with a fundamental explanation to fade price action in a big way, you might be rewarded with a home run.... you also face the risk of ruin should you be wrong. Which do you think occurs more often?
The Fed, ECB, BoE, BoJ, SNB...etc. The world's major central banks are flooding all markets with money. Where do you think it's going to go?
The central banks have been flooding the world with liquidity for decades. It wasn't a problem in the past, so why is it suddenly such a huge problem now?