You are certainly correct in your assessment: 'thinking is... dependent on being.' Descartes said, I think therefore, I am. The truth is as you observed, the reverse: I AM, therefore I think...
We pick up thinking - linguistic imagination, from around the age of two onwards - before which, there is only pure being. Therefore, being precedes thought.
You can take or leave Zen as Western philosophers have discussed the same topic and have roughly come to the same conclusions. I'm in agreement - Plato was attempting to explore the 'Absolutes of reality.'
I think you're right about Berkley - he was constrained by his times and this may have limited his exploration (though not the power of his thought).
Indeed, Constantine's Nicene Creed propagated a thorough misunderstanding of Jesus' powerful realization, opening the way for the expansion of the Holy Roman Empire and setting into place an unfortunate chain-reaction that led to the Inquisition. Anyway, no doubt Constantine knew about mystagogues, though in all likelihood, he would have saw them as a threat to his sovereignty and banned them.
No doubt mystagogues 'do take up fleeting residence in our lives.' I think you are most certainly right to use the word 'seems,' as you say:
'... it seems to be able to interfere with the sub atomic world as a particle force with indications of intelligence and purpose.'
You are on the right track with your hints about quantum 'intelligence.' However, intelligence does not necessarily indicate purpose. You are superimposing levels onto it (though to the casual eye) the mystagogue may look purposeful...
God however, has no use for purpose. A purpose only arises in time and that which is outside of time is forever purposeless. As I am sure by now you know - the First Cause of the universe was Causeless - this is logical if you think about it. Therefore, such causeless actions act outside of time and space - thus making redundant the classical laws of Newtonian mechanics. Newton though well intentioned had discovered exceedingly cleaver laws to measure an illusion whose very laws themselves were illusions. They do however appear to work - how very bizarre!
Mystagogues may very well be operating within and manipulating a number of different but interconnected dimensions: in the illusion but not of it, as it were. One might venture to say, these causeless actions are simply happenings, independent of meaning. The mystagogue may 'seem' to supplant its own meaning onto the meaningless - a kind of superimposition onto Reality. Purposes are relative and meanings are dependent on the being that uses them. All meaning is provisional at best... The mystagogue may simply be pointing you back home.
This is a fascinating topic and I look forward to hearing your poem or any more thoughts you may have on the subject.