I think John's point is sound. Correlation of textual elements does not necessarily imply causation. One has to look to more robust evidence of transmission (such as the similar or same phrases appearing lifted from the Marcan gospel; I was told recently that one of the words in the Genesis account of Noah and the flood, relating to the building of the ark, is actually an Akkadian word — that would be fairly strong evidence that it may have been influenced by Akkadian flood stories).
I would point out that there are multiple explanations for the origin and function of religion in human societies, among them, the social cohesion theory that was earlier mentioned. Others include political control theory, artifact of neurology, Jungian archetypes (or anamnesis, take your pick), as well as your so-to-speak "cultural meme" theory, that religious ideas form popular memes that are repeated and change over time. I would suggest two things. First, not putting all your eggs in one basket, especially not prior to your pet theory being demonstrated by independent lines of evidence. I'm of the opinion that the neurology is primary, but that other mechanisms can be and are folded into the service of the neurological imperatives. Second, it would seem you are guilty of some circular reasoning here. You use similarity in mythic elements to evidence borrowing, borrowing to evidence cultural transmission, and then turn around and use that recently proven mechanism to explain additional similarities as being most likely explained by cultural transmission (which itself rests primarily on other textual similarities alone). This is thoroughly improper, and John is right that you need additional lines of evidence before you crown your hypothesis the explanatory champ.
Anyway. I should go.