I think you have confused USC with a UC.
USC is a private school and not part of the UC system. There is no transfer guarantee at USC. Also, most people that want to attend USC are capable of reading and understanding how much tuition costs. Taking more than 4 years to graduate is more of a UC thing, not a USC issue. For many, the cost of a public UC parallels a private USC because it takes longer to graduate from a UC, where double majors are discouraged, unlike USC, where they are the norm.
OP, since USC meets 100% of financial need (unlike the UCs) you should get your financial info in asap to take advantage of available funding. The deadlines are not hard deadlines, but the sooner the better.