I did not read the whole thing.

Regarding "skis made to fit" vs "bikes made to fit".

I doubt is one can make a ski with a predictable stiffness
distribution. Instead, they pick skis with the right properties
(interesitng, it's like selection in evolution).

In contrast, bikes are made from tubes of defined length. If the bike
if the right size, it will fit. A ski is a more complex beast.