“To my limited understanding, they are antithetical and disanalogous to the reality of the familial Father/child relationship”.
Meant positively, that would show too limited an understanding. Please specify the “more like Buddhism” feature of the Eastern Orthodox teachings on theosis as you currently understand them. There is no “theo” (Creator God) in Buddhism.
One helpful resource: Theosis: Partaking of the Divine Nature | Antiochian Orthodox Christian Archdiocese
“without having to become mystics.”
Is the pursuit of theosis itself a problem for you mainly because of where you live?
In what sense does the opposite ring untrue with respect to Scripture. Should it be said and thought that Scripture is entirely “un-mystical” or “amystical”, and calls people to reject mysteries, mystics and mysticism? Do you possibly mean all of those as terms of friendly “reproach” (mysticism | Search Online Etymology Dictionary)?
Granted a call seems to have gone out in central Europe, early “modernity”, to become as entirely un-mystical or amystical as possible. Luther was part of a “rationalization of the world” (Weber), but so was Gutenberg on a technical level through visual bias. Should all of Christianity follow suit going along with the most highly rationalized Protestantism in demystifying the historically-called “divine mysteries”?
Is the following quotation the sort of feeling that still pervades among some over-rationalized, amystical Protestants?
“We have not the reverent feeling for the rainbow that the savage has, because we know how it is made. We have lost as much as we gained by prying into that matter.” - Mark Twain
Have the “divine mysteries” become so over-rationalized among evangelicals now, e.g. via C.S. Lewis, folks like W.L. Craig, Ravi Zacharias and so forth, who have “formulated” their rational Christianity as “amystical” because they can most easily do it that way in today’s societies they live in? Why would anyone “become mystics”, Dale, when that option is simply not available for most people nowadays living in Weber’s “iron cage of rationality”?
The recent work of Orthodox icon carver Jonathan Pageau, as joyfully and innocently outside of that “iron cage of rationality” as I’ve seen in a long time, alongside the wave of psychologist Jordan Peterson’s “maps of meaning” approach that is “pro-religious” while still uncommitted on it’s relation to Christianity, has been significant in raising awarenesss about this, as more and more people who were stuck in almost completely anti-mystical thinking, often spurred in classrooms and in media by people upholding if not promoting ideological (natural) scientism, are now starting to break down this barrier in their understanding of life, human existence and the world around us. I’m not sure if your aversion, Dale, is held by today’s younger generations, though could be wrong about that & would be pleased to hear more about it here.
After having travelled and lived in the “east” for considerable time, living in a way that is totally “amystical” sounds to me like “white man got no dreaming”, which you are welcome to interpret however you like from the Australian Indigenous. 
Btw, looking back, I thought your early comment on this thread was one of the best ones (To Capitalize or Not to Capitalize? ID Theory vs. BioLogos - #4 by Dale). Thanks for that!
- G.