Did you get the packet in the mail about financial aid? I just received it this past weekend. In the packet it acknowledged the fact that they didn't have the financial aid yet and were willing to defer the payment of fall tuition. Now, I have not read it very closely, but there are a few hoops that you will have to jump through for that to happen. I am in the same boat and do not think i can afford to pay all this upfront without any type of loans. But look into that first, then make your decisions. I am not sure if you can 'defer' your start date, but I am not positive obviously.
I have a good friend that went through UC's 4 year program and know a few others that are in it. So I am sure you will get in, don't worry about that. Just work hard and it will happen.
But you are on the right path with the questions you are asking!