Dear asamanta,

Generally speaking, rounds 3 and 4 are more competitive than rounds 1 and 2. At this point, the schools have already made many offers of admission and have had many of those folks indicate their plans to attend. Thus the number of seats available to offer in subsequent rounds is much smaller.

There is no difference in preparing for phone interviews versus face-to-face interviews aside from what you wear. You don't have to dress professionally for a phone interview since your interview can't see you.

If USC does not indicate a January entry on its website, then it probably does not have one. For a definitive answer, you should contact the admissions office directly.

Good luck,
Lisa