They supposedly don't force you to. That's unconstitutional. In my school they made you stop if you were in the hall and take your hat off and stuff. Of course I just kept walking and when they yelled at me I just told them I didn't feel like stopping and I like my hat.
As far as the flag, I see no reason to respect it. Sure tons of soldiers have died, because our leaders got into wars and sent the common folks in. If I wanna show my respect for soldiers I'll show my respect for soldiers, not this fucked up state that we live in. Showing the flag is like showing support for the ruling class. They can suck my working class schlong and wipe my jizz up with their flag. Abuse our common asses for decades and expect us to give them banner(or flag) exposures?
Die ruling class capitalist pigs. Power to the hoi polloi.