Sundering and specific character questions. [Spoilers]

[Iscah]

Of course, I can't help but think of our own moon's incidental function... it soaks up many many meteors, asteroids, and other celestial bodies that would otherwise touch down on Earth. Both small and large. Hence why it's covered in craters.

Yes and no. While it certainly has taken hits from meteors that otherwise might have hit Earth, the reason for the buildup of craters is that there is no weather or tectonic processes renewing the surface to erase them. The Moon's lack of atmosphere would also presumably mean no slowing effect or "burning up" of the descending meteor, so it gets hit harder and by bigger rocks.

It's only going to shield a very small fraction of the Earth at any one time – think about its size relative to the whole sky! – and I'm not sure exactly how much influence its gravity has but it's most likely just going to bend trajectories a bit, not "suck things in" and pull them off course.