I think what FI does more than anything else is to get the discussion off the historical/scientific order of the day and onto the big picture which is (1)Providence, God creates the conditions and kingdoms and then fills them. (2)it concentrates on the de-sacralization of the earth, in particular, the showing that the things of this world are not gods. This is the second part of the take home message of Genesis 1. 1st God did it, and 2nd, no other local god shares in His glory. Not the sun, nor the moon, nor the stars etc. They all are commanded to their places by God. But with a YECist view this is lost in the defence of the days in order. By seeing the three pairs (1-4,2-5,3-6, capped by 7) all of this alignment with modern science disappears and the religious significance of the days reappears.
as to:
3) Just because God was using natural providence (as indicated
by 2:5-7) in that instance doesn't mean he was using it throughout
Chapter 1..since obviously God was doing miraculous things.
I am still working on these associated issues, thinking in terms of the 'bias towards the extraordinary'. It appears to be a human preference to the miraculous, the flashy and showy, i am not sure God shares our attachments (*grin*). I am curious that miracles are almost always attached to a serious explanation in the Scriptures, as if the context needs to be reaffirmed to us each time. I find providence and 'normal life' creative and miraculuous, more so as i grow older, i like H.Van Til's 'fully gifted creation' idea, it pushes all the miracle to the creation of the universe and stuff, and lets Providence do the rest. But i don't think these are the big things of Gen 1, anymore than we should spend time trying to figure out how the light came before the lightbearers, there are bigger issues involved.....