Didn't he throw a planet into the sun once?
It isn't easy finding strength and invulnerability feat scans for Doctor Fate. DC says he has those abilities, but he generally relies on his magic to get things done. From a Rumbles standpoint, I can't prove that Fate has though abilities at Superman level.
He has many feats that contradict his physical stats being equal to Superman ( silver age superman that is ) . For example in JLA 74 , Barry Allen KOd him with a punch as opposed to DC Comics presents 38 where he punched superman with both fists and didn't achieve much and according to Superman it was "futile" for the Flash to attempt to fight him ( Flash more or less accepted the fact himself too )