To address your first Unique Point: The Alchemist's guild isn't -exclusively- Artificers. But Artificers, which are a rare group of people whose profession largely sprang up in recent years in a single town, are the most well known members because of their unusual method of handling things. Like I said, in a different thread about the Ashen Lands, their original purpose was keeping the sewers of Falconhurst clean and functional, so anyone with skills in:
1) Alchemy
2) Chemistry
3) Investigation
4) Architectural Engineering
5) Fighting criminals, misfits, or monsters in the sewers
Is more than welcome to join. But the class fantasy of Artificers for the setting is tied up in the Alchemist's Guild. That's also why it isn't called "The Artificer's Guild" when that would be more reasonable for an Artificer-Only group.
To address your second Unique Point: Not all Nobles or even Royalty are actually Sorcerers. But sorcery runs in Royal Families (and many old Noble families) due to the power initially bred into the bloodline by the various sources. And any Sorcerer who -is- a Sorcerer and -is- a Royal can always go Prince Harry, marry Megan Markle, and move out to pursue his own lifestyle away from the Royal Family... but everyone sill knows he's Prince Flippin' Henry wherever he goes.
Again, the point isn't to shoehorn every character into a neatly constructed box and keep them there, it's just to give players a sense of place in the setting for their character's skills, talents, and origin in the world's narrative, so that they and the NPCs have a shared understanding... Which of course can be directly undermined or manipulated for gain on one side or the other.