Really, the honest scientific answer is, “We don't know.” The slogan “reduces emissions” is actually not knowable. However, we do know, when we look at the points you raised, that it can be the case, depending on the exact source of the minerals, that an EV driven in Canada emits more carbon dioxide to the atmosphere than a very efficient, best-in-class internal combustion engine. I think that's a serious problem to sort out.
On May 13th, 2021. See this statement in context.