Regarding whether or not a personal bag would be allowed on the lifeboat, I think that's another reason to adopt the 1st/2nd/3rd line principle. Keep the absolute essentials (that will fit) in your pockets and in your small waistpack. If you've retrieved the emergency backpack try to bring it on the lifeboat. But if the mob overrules you and the bag is taken, you've at least got the essentials on your person along with the hat, sunglasses, and light jacket you should have with you at the time.

Regarding GMRS, I doubt anyone's going to be checking the freqs/bands on your dinky walkie talkies...