Everything was formed by the spinning of gas clouds and consolidating into planets and such. That's why the planets haven't fallen into the Sun after 14 billion years.

indeed, and how is that proof that the moon didn't come from a collision with the earth?

Which is why nothing has ever collided in the history of the solar system, because they all started on perfectly parallel orbits? Is that about right?

Nothing large enough to cause a planet to split into two ever collided. Yes.

Really. Interesting. What do you think was the cutoff size for objects that can collide? Can you justify it quantitatively, given your "zero percent chance" line earlier?