Non american here. I have a few questions.

1. What exactly does it mean?
2. What if you don't agree with it, for example the "under of god" part.
3. Does it have a legal status? For example can you be arrested for not pleging allegiance, or failing to have pledged at some point in your life?
4. What about freedom of speech? How can one force you to express yourself? I feel like freedom of speech goes both ways : I'd like to have the same freedom of "not speech" as well.