You can't both argue lore and then try to dismiss it when it is brought up or clarified.
Severn's gift of training does not mean that the class itself is as infused in shadow as characters (and players apparently) believe. Was there some intended bleedover for some time? Yes. Should anyone be shocked that the God of Artifice might lie to his own people to prop up this sense of being really *special* pets, in lieu of the history of the Ankyreans? The most prized and trusted rellyw? No.
As stated, Wayfarer is not native to Sapience and is offered training. The true Wayfarers do not move between cities, they are off protecting borders and hunting in Albedos, which is Hard Mode compared to what Sapience deals with. Willfully ignoring the clarity offered on this point does not serve any purpose.
Monk's one tie to Spirit is through Kaido, which is primarily the manipulation of that amount of essence inside of you rather than a link or draw from the larger element. Every mortal, even Undead, still have a bit of Spirit in them. It gets dominated by Shadow with their state, but it holds out.
Shapeshifting is a non-genetic mutation rooted in an ancient ritual. Someone being able to drop the training bears no relevance to the conversation, regarding lore or without.
I am sorry you see the well documented refund rate as punitive, but those are the breaks. I am sorry you do not find our explanations satisfying (though I will say that that is reciprocated, the arguments themselves and the attitude in which they are conveyed. This is becoming a reoccurring situation where tone clouds meaning to everyone's discredit.).
The tethers are in place for several reasons: both the mechanical balancing, as well as the lore. A Templar channeling the gifts of the Spirit plane makes little sense assisting Shadow as a Spirean citizen, just as a Sciomancer has little place warping the balance of the elements in Duiran or Enorian. There is a hard polarity with these two elements (which are physical things, not just propaganda for politics), which group some training in ways that are incompatable with others. It is easy to come up with personal narratives as to why you might toe the line, but the elements are not so forgiving once you try to immerse them within each other.