Strange question about licenses… Options

[Negalith]

OK first off, I have played shadow run for a couple years now, but have read very little of the fiction.

In a place like UCAS, does the government still issue licenses to be things like doctors, lawyers, etc? If they do, do big corps care, or do they license on their own. Because of extrataratoriatality, would a big corp hire a doctor if they liked him even if he had been striped of a license by the local government?

Also, if big corps have extraterritoriality, what prohibits them from selling their products freely out of their extra jurisdictional offices? I want that Aries 24F cyberware. Aries wants to sell as much as they can. Why can’t I set up an appointment to stroll in and pick it up? Like Native American casinos, one of the great advantages of sovereignty is being able to conduct any kind of transactions there you like despite the laws of neighboring areas. Why don’t the corps sell the products they want to sell to customers who want to buy them in a way that seems perfectly legal (particularly in a world like Shadowrun where corps are known to frequently break laws for cash)?