10 years of offshore working experience is very much sought after by many service companies. I bet you wouldn't have any problems getting into a managerial position in those companies.

Depending on what you really do. Not all work are repetitive. Since you have an engineering degree, the company would be happy to train you, and put you on different and more challenging tasks.

Offshore environment is very dynamic. You will learn something new everyday.

Yeah, I'm involved in offshore pipeline inspection. I believe others have given enough advice, unless you want to know something more specific.

Currently offshore in Caspian Sea. The best accomodation so far, with internet, a PC with plenty of games installed, Plasma TV with satellite channels and a huge library of DVDs.

You might not get a job in oil and gas company, but you can try many surveying and ROV companies like Fugro, Acergy, Subsea7, Sonsub...