A few quick questions. My parents activated their I-551 (crossed the border) but haven't got their gcs yet. Is it too early to start the application for the F2B (family preference 2B category)? If I apply for the F2B visa will that mean that I can't apply for a TN or other non-immigrant visa (H-1, etc.)? Finally, if I apply to study in the US on an F-1 visa will there be a problem if I apply for the F2B visa?