Cecilia, my perspective on this is that kids need to learn to accept the authority of their teachers, and to accept instruction and guidance. (Not to say that teachers are always right, but to acknowledge that the role of teachers and others in authority must be respected.) I think this is an important life skill. You don't want him to be 25 and getting fired for saying out loud that his boss is stupid. This lesson starts in elementary school.
I think you would be wise to advocate for appropriate schoolwork for your DS, but delivered in a context where he is being taught by an adult-- not only supervised, but actually instructed and guided. This may mean a serious acceleration plan; I would think this would be vastly better for him in the long run than simply removing him and letting him do for himself.
DeeDee
