Its really too bad Paul VI couldn’t make up his mind or couldn’t make himself take a definitive stand on the issue. He encouraged a relatively new direction and sanctioned a more modern approach but he left it for someone else to come right out and say that you don’t have to believe it’s history. He included the traditional views you quoted and then admitted the holes in them by clearly stating that the literal meaning is often not the real intent of the author:
However, since God speaks in Sacred Scripture through men in human fashion, (6) the interpreter of Sacred Scripture, in order to see clearly what God wanted to communicate to us, should carefully investigate what meaning the sacred writers really intended, and what God wanted to manifest by means of their words.
To search out the intention of the sacred writers, attention should be given, among other things, to “literary forms.” For truth is set forth and expressed differently in texts which are variously historical, prophetic, poetic, or of other forms of discourse. The interpreter must investigate what meaning the sacred writer intended to express and actually expressed in particular circumstances by using contemporary literary forms in accordance with the situation of his own time and culture. (7) For the correct understanding of what the sacred author wanted to assert, due attention must be paid to the customary and characteristic styles of feeling, speaking and narrating which prevailed at the time of the sacred writer, and to the patterns men normally employed at that period in their everyday dealings with one another. (8)
Based on the above recommendations, we can stop arguing about the misplaced literal belief in historicity of the flood, the creation/garden myths, the gospel infancy narratives, etc. and discover the meaning and intent of the authors.