6. I do not believe that a day is necessarily 24 hours. Could it have been? – yes. Could it have been more or less time? – yes. We think of time as a fixed dimension despite our own knowledge that it is not (time slows down as an object approaches the speed of light)
7. Why the earth? As a home for mankind. Why all creation? As a home for the earth. Why mankind? Because He is majestic and loving and chose to.
8. spoke, saw, eternal (he was before the creation)
The bigger question isn’t whether a day is 24 hours or what elements constitute heaven and earth. The big question is why is Genesis 1 in the bible at all. I mean, why did God tell his creation about how He created everything and the order of that creation. We aren’t on a need to know basis. It has no impact on any persons daily life (at least not that I can discern) to know that birds came before horses. Frankly, it would have sufficed and been accurate to say, “I’m God, I created everything, period.” But He chose to break it down for us. I think in large part He did it not so that we would concentrate of the beginning of the paragraphs (God said and it was so) but instead on the end when He saw that it was good. We either don’t see that or we forget it. We look at the waters and see them as wet, vast, deep, a bit scary, but we don’t normally see them as “good.” For each element of creation God wants to ensure we know (1) He is in it and created it and (2) in His eyes (the only unfiltered eyes that exist), it is good. When you fill your eyes with seeing God and goodness in all creation rather than inanimate blobs of matter, it changes your viewpoint and changes your heart. Then, we you recognize that God made this “good” comment about each part of creation up until man, when He saw that it was “very good” it changes your eyes and your viewpoint to the heart of God