Bugs or Gods?

My biggest problem with difference between Alien and it's subsequent sequels is the Xenomorph becoming more weak, I theorize it has something to do with the passage of time. For instance the Alien in the original film seemed invincible and smarter than it's brethren as did the Alien Queen, the link here is that they both come from Ancient eggs, could it be that the consciousness of the Facehugger (Memories passed down like instincts) passes through to that of the chestburster? This would also explain why the Facehugger dies afterwards to an extent. Could it be that (Suggested by the Deacon in Prometheus on the cross) that the Xenomorphs were once an advanced society that was committed to Genocide and the remainder put into stasis with the passage of time driving those in stasis insane? Into nothing more than animals with only the glimmer of Godlike intelligence left? (The Original Alien & Queen) with the insanity passing down the bloodline making the Alien less and less human (Warriors in Alien) and more and more an animal? That what if in some twisted fashion (As the Black DNA clearly has relation to the Xeno) the Engineers harvested this from the only other life they could find, of course later they would realise they were too dangerous to breed and committed Genocide (The Space Jockey on LV-426 could be one that was lost in the chaos as it was clearly seen that the Engineers use the Aliens as a biological weapon.) The first they find however could be the one "Pure" Xenomorph and in essence spreaded it's DNA (Using the Vases) to create life (The beginning of Prometheus) so that, always as Ridley wanted the Alien was not only Godlike. It is in fact God. What would you think of this kind of reveal/something similar in Prometheus 2?