All exceedingly good questions. To which I'm certain there's a mountain of non-disclosure agreements burying the answers. Additional questions, how is it legal, let alone MORAL for a CHILD to enter into a contract that gives a private profit seeking company sole financial control of them as an adult. This includes having to "pay back" training costs that no one will ever look at to see if they are reasonable or even realistic. In the US it's illegal for a child to enter in to ANY contract for ANY reason. Their parents can sign, but also, since that child is part of a legal agreement, they MUST have a court appointed attourney that represents them and them alone. It's not a perfect system and children still get screwed but at least it's something. Also, in almost all cases the court is known to side with the child so companies are wary of legal agreements that involve children.
So how do the Disney contracts work ?