LOL, you don't get court martialed for insubordination.  A Company Grade Article 15 maybe but not a court martial unless the accused requests it. 

The accused can be ordered to request a court-martial.



And the UCMJ doesn't apply to the parent. 

How is that possible? The parents are speaking on behalf of their kids, and thus are equivalent to their kids.



And treason doesn't even come into the picture here.

Not possible. ANY disagreement with the Commander-in-Chief, on any topic and at any point during his life, constitutes hatred of and opposition to America. That is the definition of treason.