It was hard to follow exactly what is going on, But you have a coupld of nulls to animate the camera moving goth vertically and horizontally over the earth.. I would animate the camera moving as well to help smooth over those strange movements. ..And if that does not work perhaps use less animation on your nulls and more on your camera. Once you have two position points on a camera, its nice to go to the top view, using the pen tool Like you would a mask path, turn those straight camera paths into rounding arcs around your earth.