Excellent references!
That scene you reference with David was just fantastic.
“Why did your people make me? We made you because we could. Can you imagine your disappointment for you to hear the same thing from your creator?”
And then David does what he did.
Brilliant, brilliant stuff.
And then your reference to Fury’s statement on bigger WMDs...
The Engineers had the biggest WMD of all, so big in fact that it could potentially be a universe killer, so big that it killed them, but not big enough to kill its other creation, man.
And in the last scene, why did she truly want to go where they came from? I believe it not for any answer to any question, it was to do what man does best, and that is deliver a payload of destruction.
And the ending! It’s full circle. One of my favorite Larson cartoons shows little Aliens at their Thanksgiving table. One is tattling on another—emerging from a turkey.