1) Everything from disappointment to anger to shouting.
2) But, the "Story Pole" (as it is called) is the ultimate decider.
3) And, yes, some kids are required to remove shoes if the CM thinks the soles are making the kid too tall.
NOTE: The restraint systems do not account for think soles. So, for protection, it is the actual height that matters. If kids are too short, then it is something the parents have to deal with, unfortunately.