Doesn't follow. God can't create a rock so heavy He can't lift it so omnipotent simply means being able to everything that is possible to do at most. Obviously, God is omnipotent relative to man.
So your argument is that evolution is the best God can do?
Not necessarily. Although it stands to reason that whatever God does is the best He can do. But it IS a fatal flaw in your argument.
God appears very limited if he has to resign himself to a process that takes 4 billion years.
Why is this a problem?
This seems an unlikely scenario for a God that can part the red sea, heal the sick, turn water into wine, and walk on water.
Perhaps those are reserved for the blessing of the faithful or warnings for the unfaithful. But it's not up to me to find answers for what is. Why does God have us going through an inefficient sexual process to reproduce and why don't we just appear on earth as adults and not have to go through the stage of childhood?
So evolution through supernatural selection.
With the right initial conditions, I don't think it would take more than a few nudges imho.
With God himself guiding this process it takes about 2.8 billion years from the first single celled organism to multi-celluar organisms. Nearly 3/4 of the total time is spent on single celled organisms. If God had his hand in the process you would imagine that things would have progressed much quicker.
Why would He not be satisfied with natural process? Perhaps He's bound to them and knowing them far better than we do, can use them.
It seems an odd coincidence that God opted to use a process where his influence is completely invisible.
Any way you go, Creationism or Evolution, it's invisible. But the effects are not.