Before Theodwulf posted this thread we discussed briefly on Twitter about this subject, and I think it's worthwhile to repeat what I said then. Please don't consider this confirmation nor rejection of his theory, as I just want to add some pertinent details.
The Hinterlands we see in Minotaur Hotel are based on real life places, but mixed together with other ideas and with fantastical details for good measure. I had a very large pool of very real things I wanted to put in that section of the game, but seeing how big it already was I made an effort to condense ideas into small details. In the case of the Mary allusions, on some level I wanted to portray the prevalence and importance of her figure in the local culture. For example, every day at 6PM the radio stations would play an Ave Maria. Every home has a statue of the Virgin Mary, and I've known couples who were gifted a statue of her as a wedding gift — and for them that is a big, very important tradition.
So, in case someone ever thinks the allusions to Mary were just coincidences... No. We were extremely deliberate both with their inclusion and with their proximity to P. In fact there are more of them which, it seems, people have not noticed yet. And we would have gone further with this and other associated motifs, if only we didn't have to cut them to rein in the scope and simplify some otherwise complicated technical things.
On this general topic... There are many things to the setting of Mino Hotel that we just couldn't find a place to put in the game just yet, but which we wanted to be in already. One of these things is that, in the Mino Hotel universe, the Panoptes peacocks were some of Hera's most favorite and dearly cherished creations, and they were very loyal in their worship of her. We couldn't see it just yet, but P dedicates a great (but perhaps infrequent) deal of respect to her as well. Is it any surprise that this bond between these two parties would become a recurring aspect of the Panoptes?
To close it off, one thing I will confirm is that your description of P's magic...
the KIND of magic we see P practice, and Storm learn from him: utilitarian, symbol-is-the-thing, ritualism put together from The Things That Happen To Be At Hand.
...is extremely accurate.