And about the tides...

THe gravitational effect of a massive body decreases as the square of the distance increases. Basically that means that a smaller body that is much, much closer (like the moon) can have a greater measured gravitational effect than a larger body that is much farther away (like the sun).

If this weren't true, then we wouldn't have any tidal effects from the moon, but we would have tides from the sun. Gravity doesn't play favorites and "controls the internal behaviors of our planet" only, as you say. If The sun had such a great gravitational effect on our planet that it could stir the core, then it would undoubtedly cause tides in the ocean's as well.

The moon's local gravitational effect on Earth is much greater than that of the Sun (remember the distances) because it is basically next door. Think about it, the Earth is going fast enough to orbit the Sun with less than 1% eccentricity, but the Earth still rotates on its own axis, so the Sun obviously doesn't have enough of a tidal effect to rob the earth of angular momentum through tidal effects and slow its rotation. Now look at the moon, which is tidally locked with one face towards the Earth. Obviously the Earth had enough of a gravitational effect on the moon to slow its rotation until one orbit equalled one rotation. This happened through tidal effects (basically the moon ain't round no more), and any effect the earth exerts on the moon, the moon has to exert on the earth, or else it wouldn't be there. If the Sun's pull was as strong as you imply, we would orbit the Sun much faster, much closer to it... and we wouldn't have a moon.

As far as the moon's influence in the development of life on Earth, such is mere speculation, not science.