Yeah, but don't forget about the heavy-handed religious metaphor of it all ;) Just because the "creator" used "part of themselves" to "create life on Earth" doesn't mean that the product of life on Earth (us) is then literally the same thing as the creator.
Okay, just so we're clear, the Engineers aren't human. Humanoid in appearance, sure. But Charlize Theron, Idris Elba, et. al. are the humans in the movie. The Engineer is still an alien, don't worry :)
That's basically exactly why I got PROMETHEUS :) It's definitely worth it, in my opinion. It's essentially identical to "Dangerous Days" and his "Alien Anthology/Quadrilogy" docs, only longer and more in-depth (if you can believe that).