On the magic shop, et al aspect, that’s where I diverted a little having the various other cultures:
Norse: Learned Magician, Folk witches, Sea/ wind wizards (elementalists), Trollsynir and Vitki accepted into society, not outside it.
Munter (stocky humans): Learned Magician, Mythic alchemists, Folk witches, Necromncers, and Sahirs are parts of the society like the military, nobility, religion, hence even closer integrated into the society.
The outcome of that was a much more common distribution of the use of magic, particularly if you consider that these cultures have a higher literacy rate with their hedges. Starts to make the Order seem a little “repressive”.
Having a magic item shop is super fun as a thing, and my dreams of doing so will have to come to fruition sometime. I could easily see creating a bunch of charged items that you sell to adventurers who collect materials from Regio (which from my own understanding are close enough to the concept of a dungeon that its an easy mix-and-match) which they then sell to you, thus giving you vis and things like skins and diamonds etc. Actually, this sounds like a super fun character concept here... Imma have to use this.
Speaking of fantasy setting things, I've been rereading the faerie and magic realm books to flesh out those two portions of my fantasy setting, and there are so many interesting views to borrow or alter. Additionally, I purchased ancient magic, hedge magic, and some other books to expand my collection and there are some things in those that make for amazing worldbuilding questions and answers.
Egyptian mummies using canaanite necromancy and ars goetia to pull off something akin to gruagachan external souls, except totally different. Using canoptic jars as arcane connections to their dead selves in order to have their sarcophagi summon them and then bind them into corpses created by CrCo rituals built into them and powered by their (admittedly also likely dead) servants who put in Vis.
A bunch of gruaguchans who have turned into trolls in retaliation for their families being slaughtered, trading their sanity and control of themselves to Gruaguch in return for their external souls being hidden away and protected, thus requiring them to be petrified and held in a secure location to prevent like 50 trolls or more (potentially way more) from rampaging unstopped.
Hephaestus being replaced with a dwarven ancestor who uses the sacrifices verditius wizards make in order to feed and grow as a faerie, thus giving a reason for house verditius to have initiations for faerie blood to get the dwarf bonus.
The entire world existing within a strength 3 magical aura (more magical creatures, more vis, more magic everywhere) to facilitate the high fantasy thing (thank you whoever gave me that idea, genius)
Races like elves and dwarves are faeries, but because faeries are A) rare, and B) less able to change their glamour or role, you can have them as fun fantasy races that are as supernaturally good at things as in DnD or LotR.
Beastfolk are an easy one-to-one for magical humanoids, and since they are my fave fantasy race, I just had to add them.
Angels and demons being true opposites in that gods take souls that are saintly, purify them of mortal concern, and bam, angel. Demons are thusly tainted by their mortal concerns and the "sins" they committed (essentially like a mark left by the negative feelings others have towards them) which taints the soul into being unusable for the cycle of reincarnation. Yes, I HAVE read the infernal realm book. No I HAVENT read the divine realm book. My priorities are straight as can be here.
Grim and Jolly reapers. Grim for the bad people who aren't yet demons, and Jolly reapers for everyone else, because death should sit down, invite you for drinks, and wanna play dice. Challenging the grim reaper to a game just doesn't feel likely, but with a more Jolly reaper, I could see something like that happening easily.