"Two, "International Waters" are defined as two nautical miles from the shore, and the NW Passage is wider than that."
Canada's "Territorial Waters" are defined as extending 200 miles from Canadian Territory. The North West passage is bounded on both sides by Canadian territory. So the Passage is an inland channel or straight. Is not an international waterway.
I don't where you got the 2 mile definition. Are you saying all waters 2 miles off the coast of the US are international waters?
200 miles has to do with a country's exclusive economic zone, it has nothing to do with territorial seas when it comes to a right of passage.