I can see where Trade Class might be matrix-ed against Tech Level to determine default skills. For instance, a person from an Ag-world with a TL of 5 or less would likely have Equestrian-0 as a default skill, a person from an Ag-world with a TL of 6 to 8 would certainly have Vehicle (Ground)-0, while another person from an Ag-world with a TL of 9+ may even have Robot Ops-0.
Some worlds would have a certain minimum TL. For instance, an Asteroid Belt would require a minimum of TL 7 (for space travel) just to have Vacc Suit-0.
I like the idea of specific default skills being acquired for each career type. Going by Supplement 4, Citizens of the Imperium, we could have five skills per profession, with the player's option to choose any 3:
Barbarian - Brawling, Hunting, Survival, Tracking, Weapon
Belter - Broker, Prospecting, Demolitions, Vacc Suit, ...
Bureaucrat - Admin, Bribery, Broker, Computer, Legal
Diplomat - Admin, Carousing, Liaison, ..., ...
Doctor - Admin, Computer, Dagger, Instruction, Vehicle
Flyer - Admin, Communications, Computer, Electronic, Mechanic
Hunter - Brawling, Hunting, Survival, Tracking, Weapon
Noble - Admin, Instruction, Leader, Legal, Liaison
Pirate - Brawling, Blade Combat, Broker, Gambling
Rogue - Brawling, Bribery, Forgery, Gambling, Streetwise
Sailor - Admin, Communications, Computer, Electronic, Mechanic
Scientist - Admin, Computer, Electronic, Mechanic, Robot Ops
(Disclaimer: I did these "off-the-cuff", so your results may vary)
It could get really complicated, really fast.