Thank-you for posting your interesting take on alchemy. I was surprised that you did not examine the elements: Earth, Water, Air, Fire and Ether; which are a basis of not just alchemy, but the world view until about 200 years ago. I believe understanding the elements become essential when understanding the world view that existed when various ancient religious literature was composed, because we can understand that literature even better.
For instance, there were symbols associated with each element. The pyramid was the symbol for fire, and this is exactly why the Egyptian pyramids were built, because Egypt is a very hot place, so Egypt was symbolized by the pyramid.
Or in the Christian Gospels we have Apostle Peter. When we look deeper into the original languages of the Gospels and Jesus and his disciples, we find the the personal name 'Peter' actually mean 'rock' which is interpreted as a strong foundation for the life and teachings of Jesus. However, if we examine it from the world view present at the time we find, no, calling Peter, "rock" was Jesus saying how earth-like he was, which was to say he was slow and stupid.
So, I recommend in your book you spend some time exploring the elements, their symbols, and meanings, because they were at the core of the concepts within alchemy.