On the plus side, container ship drag races would now be a thing.

Imagine how far they travel when trying to stop. I guess you would have the power to run the engines in reverse at full power too.

Power isn't the problem; vibration, the stress on the ship's hull, and risk of losing a propellor are the real problems with sustained running in reverse at full power.

Stop ? Just drift with all your cargo.

You'd get surprisingly little additional speed. An old rule of thumb is that if you double the power of a large ship, you get 4 additional knots of speed. Current average laden container ship speed is ~15 knots, down from about 20 knots from back before they cared about fuel costs and emissions. So you'd only get speeds up to what they were before.

I think the 60MW output is shaft horsepower so it already takes into account the low efficiency of converting fuel oil to movement (so in reality it's burning about 150MW of fuel oil).