re: How bad would Bama be screwed if Saban waited to retire at season's end?

In all fairness, imagine putting yourself in the ADs position of having to replace Saban. That would be extremely difficult to do, there's just not many people in the world that's capable of what he's done.
When he left LSU, LSU was lucky with Miles. They had no idea he would turn out to be as good as he has been.

Eventually some other coach will reign dominate, but how does one go about finding them and timing it to land them? No easy task.

No he is still thinking he has a shot at a natty. LSU should fix that for him this weekend.