I worked my way through your links and acknowledge that you have spent considerable time and energy in your research. One aspect of the Giza plan which has intrigued me is the location of the bottom right vertex of your triangle with Heliopolis as the left vertex. Have you searched for it in the Western Desert?
As for Precession of the Equinoxes, I am onboard with the phenomenon. However, not to its cause or length.
Most likely, there was a cosmic impact in Central Asia. I have been interested in this line of research for some time, and satellite images confirm the distinct possibility of such an event.
But I am not convinced that precession is a result of this impact.
I am more inclined towards seeing this event as changing the obliquity of the axis. Perhaps, the Earth was once upright and had a 360 day Solar Year (Golden Age)- and experienced no seasons (Genesis 2:4). The cosmic collision may have not only changed the angle of obliquity but also slowed down the period of revolution.
If the timeline of Antarctic ice is correct, then this event happened at least 800,000 years ago.
Precession was already occuuring at the time of impact due to the effects of being in a Binary Star system. It's the Sun, and hence its satellites ie the entire Solar System, which has a "wobble". The effect of dual elliptical orbits accounts for why the Rate of Precession speeds up and slows down. Neither a lunisolar theory, nor a collision event can account for this anomaly.
But, there is more going on with respect to this whole matter, which bears further discussion.