ICANT'S position in the creation debate

Everything is an "observer" of everything else because even an atom will react to the presence of another atom, either by bouncing off of it, bonding to it, or being repulsed around it via electrical opposition. Observation does not mean consciousness.

Now you're throwing in another concept you don't seem to understand. Dark matter doesn't permeate all of space. It probably exists much like normal matter, clumping due to gravity. Also, one of the defining characteristics of dark matter is that it doesn't interact with photons (thus the name "dark) so it would have no effect on the speed of light other than due to it's gravity.

You do realize that the mass of the moon doesn't actually disappear and reappear when the moon waxes and wanes, right?

Yes, but all you need to calculate is the acceleration caused by the Earth and the acceleration caused by the moon. I would guess, based on the respective masses of said Earth and moon, coupled with the proximity to the Earth, that the effect due to the moon is negligible...however, I would also bet that it's been taken into account.