A couple of notes. There are more single-engine helicopters in the GOM than all other types combined. All the accidents I see are single-pilot, whether one or two engines. There have been accidents involving 2 pilots, but not many, and not lately. The PHI incident where the tail rotor separated on the 412 is an exception, but from what I read the fact that there were two pilots was what kept them both alive, and only minimal damage to the helicopter during the incident.
I don't think there is a typical GOM operation or leg length. I've flown jobs where I did > 100 takeoffs per day, and 3 miles was a long flight. I've also flown jobs where almost every flight was > 100 NM. All things considered, I suspect that if you average everything, there are more takeoffs per helicopter in the GOM than in the North Sea. But the regulations are very different. I don't defend all our regs, but you must remember we have to live with the ones we have, and fly to the edges of them. That's just a fact of life (sometimes death) here. If you're afraid of flying single-engine helicopters in poor weather, better stay across the pond.