There are, of course, more controversial words than God. God is probably edited just to not interfere with religious beliefs.
As far as damn, it is in the group of words like ass, hell, whore, and bitch. Radio stations have the option to play those words or not.
For example, like Eminem's "Just Lose It", he says "yeah boy shake that ass". Some stations played "ass", some played "butt", and some just edited it completely. It was the company's and radio station's decisions ot keep that word.
Same goes with "sound-alikes", most common offenders being Black Eyed Peas' "Don't Phunk With My Heart" or in {ussycat Dolls's "Buttons" where it sounds like "Hollywood type of "fu*ker", while not as bad, was and still is edited on some radio stations.
But very offensive words like fu*k, sh!t, and so on, radio stations have no option but to eliminate them completely.