Could the significance of 2012 really be that it may change the Apophis's current course? ?

Jose said it well. I bet you $1000 that nothing disastrous happens in 2012. Some charlatan invented nonsense about the Mayan calendar, e.g. greatly exaggerating its accuracy. If it was really so accurate, we would switch to it from our Gregorian Calendar. What do you mean by the galactic equator? That has no significance, even if we were, but we are not. Gravity is not the same as electromagnetism. Take some science courses and stop reading nonsense.