Welcome to the Newschoolers forums! You may read the forums as a guest, however you must be a registered member to post. Register to become a member today!
I know you really aren't a designer, or thinking big picture, but with each suggestion you have to look at the ramifications and question why designs haven't changed drastically.
Ski boots will never get away from have a rigid structure. Because of how boots interface with skis and the angles and design involved with skis, boots must be stiff in order to A) perform well and B) prevent injury. When considering performance, you have to consider that having a softer boot, or a multi-piece shell design would require much more work on the part of the skier for far less precision. But most importantly ski boots are designed for safety. To make them softer with more flexible materials would means much more pressure and force/stress on ligaments and tendons in the ankle. Small bails would result in tearing all sorts of ligaments and could also result in more broken bones. You aren't comparing apples to apples when you analyze snowboard boots; the snowboard binding system secures the foot, not the boot, whereas in skiing, the opposite could not be possible with front to back movement whereas snowboard movement is lateral.
Also, your suggestion for leather or other coverings like snowboard boots would not work for a ski boot. Ski edges are sharp and pulling a mute too hard across or bailing and having your ski crash into your boot at high speeds would put huge gashes in it, resulting in damaged boots that people wouldn't want to wear within 5 days on the hill. The outer plastic is for a reason.
Anyway, I don't want you to stop thinking of ideas, but be aware of perhaps why boots haven't evolved significantly.
stiff/hard boots are a must or else there will be more injuries
i didnt buy the flexon hype until i tried a pair on. I have havent even ridden mine yet and ive allready noticed a difference in my skiing theyre that good! figure that out