1, American university tuition is accumulated by project, and I20 gives you a price similar to "standard configuration". But if you want to take more courses (or fewer courses), the cost will increase or decrease accordingly.

2, the university will have some basic courses, if the credits you have studied have been recognized by the school, you can avoid taking them.

3, it should be ok. You have to go to school and have a special teaching assistant to negotiate with you. Because the choice of some courses is conditional. For example, if you take a class, you must take a class B before you can take it. Class b may be related to C. . In fact, it means that you have to fix a relatively basic course before you can choose an advanced one.

If a major reaches the graduation standard, it needs to get all the required professional credits, plus other elective credits. . . . As long as you reach the total credit. . . . Therefore, the credits of ap exam mathematics, physics and biology can be deducted. But if there are more, sometimes some credits will not be used. For example, science credits for art majors only need 6 points, and you have 12 points, which may be redundant and useless.