I don't mean to nitpick, Tom, but is this really your plan?

Ah, I see what you're saying. And I... halfway agree with you? It's hard for me to separate this narrative from later events, but even so, I think they made Magneto's goals fairly clear from his conversation with Shaw. As he said, he agreed whole-heartedly with Shaw's speech about mutant superiority. He may not have advocated nuclear war to wipe out most of the planet's population, but that only means he's not crazy. And even earlier he made it clear that he thought that mutants were naturally superior. (The whole chess scene with "we already are the better men," and a couple others that are escaping me right now, drat.) So while his shift to "war upon the humans and creating a comic-book science machine to forcibly change the race of the world leaders" isn't present in this movie, his ideals of racial superiority, I thought, definitely were. And even if I didn't know how Magneto ended up the implications are still pretty clear. My mom saw this without any other knowledge of the X-Men, for example, and even she twigged to it.