1: You should consider the fact that basically the entire cast so far are highschool girls. On top of that, as the OP says, there's already probably some degree of power boost that comes just from a contract. On top of that, your character gets more powerful in the event that she's not going to win. On top of that, she gets permanent power boosts any time she wins anything.
2: If her club's built around assorted competitions, which she will win, because she always wins, then those miniscule boosts will stack up over time.
3: So, basically, that entire power does absolutely nothing and won't be there? Good to hear.