Check the visa category. Perhaps marriage disqualifies him. Perhaps the visa category allows dependents. And perhaps not.

Normally you get a notice if the visa is revoked. Revocation does not mean you are out of status or that you cannot change to another visa status.

To let go of something right away is to release forthwith.

When the child turns 21, he or she can file a petition for you.

Since there is every reason to believe that he will not keep to the terms of his visa, it is correct to refuse to issue the visa, and to revoke it.

If you have timely filed to change or extend your status, and that application is still pending, then you do not have any period of unauthorized...

No it is not a crime for you to apply for a student visa. Nor is there any law, as far as I am aware, that precludes the spouse of a G4 visa...

When she returns to the U.S. she will get a new I-94 and the date should match yours, unless her passport is expiring.

Perhaps the security checks are not complete. Perhaps there is some other eligibility issue. Perhaps it is an oversight.

Maybe you will not need any interview. Maybe it's your work card.