But she's not Space God (although she acts like one, which I hope they address a bit more at some point.) What she's talking about is a nudge, not mind control. Ancient humanity had power armor and advanced AI, so it doesn't seem a stretch to think we'd eventually get there independently again.

I think a lot of confusion about this stuff comes from a fundamental confusion over what universe people think Halo is. What makes Greg Bear's books so great to me is they feel weird and alien and un-Halo; thematically they reinforce the idea of the Forerunners being this powerful race that isn't like us (but also is, with their tragic downfall.) But 343, wisely, has shown zero interest in trying to create that atmosphere in the present day. It wouldn't work. "Modern" Halo is a military sci-fi universe, and you can stretch it in different ways (add a dash more Star Trek, incorporate film noir elements, etc.) but it couldn't shift to a more high sci-fi or fantasy blend like a Frank Herbert world without feeling really off.

And that's why the complaints of "Chief is being controlled by a geas! He's actually going to be Lord of Admirals!" etc. Don't make sense. For one, those geas we see were specifically implanted at birth by the Librarian. She doesn't have that control now. The best she could do was try and stack the deck as much as possible so that humanity would develop the tech she felt was necessary to reclaim the Forerunner legacy. And 343 has shown absolutely no interest in bringing that sort of stuff to the fore of the Halo games, for good reason.

The "Reclaimer" cutscene is pretty pivotal, and I agree that it ultimately doesn't hold up in doing what it needs to. (It probably would have been better with some of the original cut lines that models found in the game files, although I don't think it would still have been clear enough to avoid confusion.) But she was never saying that she is humanity's puppet master.