More later, but I want to say that I agree with your first point, Andrew: it’s impossible to miss the parallels between the Genesis 1 creation narrative and the blessing on Noah. These parallels highlight the continuity between the two events, both of them playing in the same register. From within the corrupted world God chose Noah and his family to embark on a renewal and a purification of the old creation. Periodic renewals and purifications are characteristic of the Old Testament narratives, most of which deal specifically with Israel as the chosen microcosm: their separation from the world as a chosen people; their periodic disobedience, punishment, and repentance as indicators of God’s continual and specific concern for their well-being; and God’s use of the unchosen macrocosm as his usually unwitting agents in dealing specifically with Israel.

This is all old-creation stuff, says Paul; it died on the cross. Paul never uses the biological be-fruitful-and-multiply formula in describing the new creation. That sort of language is inadequate to describe the radical break created in Christ’s death and resurrection. Also, repeating the old-creational tropes would likely trigger old-creation associations especially among his Judaizing readers, and Paul is relentless in insisting that the old paradigm of separation and purification of a chosen race no longer holds.