Here, there are very few accidents caused by alcohol, (It being illegal in this country and really expensive to get hold of). but this country ranks int eh top five for car accidents and fatal car crashes in the world. The country only has 3 million people and yet has more fatal crashes than most of the rest of the world..... You get the idea about true reckless driving.
I usually go with the flow of traffic, approximately 90mph and up. The crashes are unbelievable. People here do not survive without the seat belts. I stop at many of the wrecks because my medic training is higher than many of the EMS here. Ejected, means dead. Don't even try to rationalize it otherwise. The laws of physics alone tell you that, not to mention the car rolling over you at ejection, or the impact of landing. Roll overs will kill you if you are Not restrained. Clear and proven. Anomalies are just that. Seat belts cutting throats- oh yeah, that is a huge problem.... no..
The rest of your examples are just too out there to respond to.
You may rationalize and beat your chest about your reckless decision all you want, but at the end of the day, you are still being reckless and foolish.
You go to all the trouble of fashioning a fake seatbelt, why? If you are so proud of your self, you should take that stand. Otherwise, obey the law.
As to boats, I don't know how feasible it would be, but I have ridden a few high speed jobs and they had restraints. But they were racing boats, not large transport. I defer to Onespeed, as he is in teh boating industry. My husband designed yachts, but those were all over 85ft. No seat belts.