Carrying on your instrument onto the plane, at any rate. D’you have a copy of the letter sent to the AFM by the US Transportation Sec Admin? You can download a copy at http://www.zinalee.com/images/carry%20on.jpg
I’d carry a copy of the letter with you. Allows you your instrument in case, one bag, and one personal item.
Hopefully this won’t be different during war. *sigh*