An interesting essay. My interest in this is very limited as I find religions as they exist now to be devoid of any social value. The very clear movement now away from religion and toward personal spirituality is, I think, the final end of the old religions and the beginning of the restoration of spiritual health to our societies.
While that process of spiritual growth is based on what works for you I’m very leery of using mythological elements of the old religions. Those things carry far too much ignorance that can leave anyone confused at crucial times. Because the stories were invented, whether in whole or in part, they were inherently prone to multiple versions and contradictions.
Your identification of the story of Mary Magdalene is a good illustration of the problems that exist with centuries of arbitrary stories presented as actual history.
There is almost no valid information extant on the establishment of any of the surviving classical religions. In our world validity of information is critical. Personal justifications built on bad data are prone to collapse just when we need them. The vicious attacks on truth that we live with daily in the collapse of the American political system show what can happen without a very high degree of care concerning truth. We are just beginning to learn that.
In the past this was not really an issue for the vast majority of people. In the data driven world it is very much an issue. We no longer have the freedom to act as if arbitrary stories are real except as abstractions or ideals.