A few points here:
Noah's birds had to wait some time for green things to begin growing again...
An open pit mine is down into rock. The Flood left approximately two miles of carbon-rich sediment across the face of the earth -- excellent growing material.
Animals did not starve to death; they drowned.
Floating vegetation mats are seen after the monsoon seasons in the Far East. There is no reason to believe even larger mats were not set adrift on the seas during the Flood, where much vegetation, insect and reptile life were preserved, and which helped repopulate the land earlier.
If you want to know what happens to rock geology with rushing waters, don't look at the ocean, look at the Grand Canyon, the Columbia Gorge, or Engineer's Canyon (Mt. St. Helens). All were carved suddenly.
But again, the Flood left first a deep layer of rocky cobbled material cemented together (diamictites) and then, on top of that, about two miles of carbon-rich sediment (exactly what should be expected from that kind of catastrophe). Remember that ALL the springs of earth exploded at once at the initiation of the Flood (Genesis 7:11) -- this would have brought up tons upon tons of pulverized earth material which, when combined with the rotting carcasses of the multitudes of life on earth then would result in exactly what we see -- the two miles of carbon-rich sediment.
As the waters drained into the ocean beds (newly collapsed from the explosions), the vegetation mats would have either drifted onto land or been stranded on the land, thus providing already growing material to be spread into the surrounding areas.
We do NOT know where Eden was, although in giving Israel and even a larger portion of the Middle East to the Israelites, we may have a clue that God is giving us as to the former location.