The competitiveness of your high school is one of the nine additional factors considered during your application review. It will be used only in a positive way. The competitiveness of your school will never hurt your application. This is where questions are answered and tests taken. A large lecture will always be tempered with a smaller recitation.
Some professors use television to supplement their lectures.
There are some courses in which the lectures are videotaped and made available to students for review or if they missed a class. A full-time load is 12 hours. It's certainly possible, but most students nationwide don't graduate in four years. At Ohio State, many students choose to participate in cooperative education programs, internships, and study-abroad programs, which will delay graduation beyond four years. Many students also choose to take off a quarter or two to work or to meet family obligations.