Obviously the trade off for the stability is not a very fragile boat. A boat with that stability characteristics used has a fast cruising boat (and not raced at mad speeds) would be hugely strong.
Most of the motion discomfort on these boats has to do with speed. If you go only at 3 times the speed of your boat the comfort would be completely different.
Absolutely not.. hull design has everything to do with rough water capability..
AS a mater of fact, the racing boat is much better off at a higher speed in rough water to take advantage of its hull... Same as a power boat..