It'd be interesting to show Superman moving the Earth by means that go beyond "pushing on it". As an example, Superman could grab the biggest asteroid he could push without breaking it up, and loop it near the Earth repeatedly to cause a gravitational sling-shot effect.
In SCIENCE OF SUPERMAN, Wolverton mentions that there may be limits to Superman's powers, simply because it's very hard to imagine a human sized being wielding that kind of force. He mentions, though, that it may be possible for Superman to use some sort of device to make his work easier. Most people cannot, for instance, pick up a car, but nearly anyone can with a jack.
My question is this: what sort of "jack" would Superman use to push the earth around?
I'm not saying that extensive research automatically leads to great writing. But it certainly helps. And on any list of great authors, the researchers will tend to top the list and the screw-ups will place high but not as high.
No arguments here. When it comes to writing, you get what you put in.