Not sure if you are familiar with helmet testing procedures but making a helmet too strong is just as dangerous as not making it strong enough. Even if you are borrowing pads from other helmets you're basically making something that could mess you up almost as much as not wearing a helmet.
http://www.pinkbike.com/news/Video-Helm ... -2012.html
Watch the video, Bell kinda knows what they're talking about.
Hm. No, you got it wrong. The current shape is strong, but after cut into a desired shape it will be flexible.
Take an egg or a ping-pong ball for example, or a half sphere. It is strong but when it's cut like an orange not strong any more.
Also not correct with "borrowing pads" since almost all water helmets are padded but glued. Not possible to take out. The "white water" kayaking helmets are not padded, they are more like a climbing helmets.
Many skydiving helmets are carbon cevlar and Hiko in the EU made heaps of kevlar helmets for a "white water" as well.
Lastly, we are dangling on a 25m lines. Certified? Not. Even a scuba tanks must be tested each year:)
I like Australia where the bicycle helmets are compulsory by law. And than Holland with 13mil bikes has no such a law and less ppl die while riding...Even Schumacher is still in a coma, remember?
Helmets do not protect from broken neck. Ideas? Please do share.