Aren’t parents/guardians required to sign the Early Decision contract? If so, OP needs to make sure his/her 'rents are on board with that.
UChicago isn’t going to go after someone for the tuition dollars. What they might require, however, is that OP stick to the binding agreement which includes both immediate acceptance and immediate withdrawal from all other universities. Should OP find he/she can’t attend - well, that could be a bit of a sticky wicket. OP will have to go back to all those colleges and explain that he/she didn’t stick to an ED contract. Should OP opt NOT to fulfill his/her agreement to withdraw, that risks nullifying the ED contract with UChicago and/or perhaps even a rescind from other institutions. Just not worth it unless, as UChicago states: you are certain that UChicago is your first choice AND that you would attend immediately if offered admission.
UChicago might have significant merit scholarships and need-based aid but ED doesn’t give the applicant any bargaining position. Quite the opposite. Logically, UChicago is more likely to devote those resources to the EA’s who ARE comparing offers. When you go ED, you are contractually professing a commitment to the school in exchange for an edge in the admissions pool. Unless there is a clause stating otherwise, it would be foolish to view that contractual commitment as anything other than what it is - a contractual commitment. UChicago certainly views it that way because they say so on their website.