Is UofSC South Carolina? I figure that it must be because U of Southern California would not be “extremely likely” with a 3.5 unweighted GPA.
Is U. South Carolina really better than the various SUNY’s? In-state public schools are usually more affordable than out of state, although there are exceptions and maybe this might be one.
I would only apply ED if both the school is your clear top choice, and the NPC shows it as likely to be affordable or you are fine being full pay.
And keep in mind that these days “full pay” is getting close to $100,000/year at some schools. Given how strong your in-state public options are in New York for some of us being full pay at a private university might not be worth it. This will however vary from one family to the next, and can be a tough decision.