I think the Amazon Trio would be professional alcoholics. I love them--they're super high on my favourites list--but I can't imagine them actually doing something that wasn't hanging around, drinking, and talking about how good-looking they are. However, I'm sure that they would have actual dreams and goals once they are actually humans instead of just high-level lemures...but I can't shake that image of them at their bar. Maybe they can all take up bartending and open their own dive bar.
As for the 4 kings, I think Nephrite would be a great talent scout. He was pretty convincing in various public-facing management roles. He is aggressive, but not in a way that seems to alarm people, so I think he'd succeed in a job where there is a lot of persuasion and take-charge attitude needed.
Kunzite would probably adjust well to work in law enforcement. Not something that requires too much interaction with strangers; he's pretty harsh. Maybe a crime scene investigator or a forensics expert. He seems to have an eye for detail.
Jadeite needs a job that isn't too stressful after everything he's been through with Beryl. XD He was always getting reprimanded. Maybe he winds up working odd jobs for short periods of time.
I imagine Zoisite operating a spa. I think he'd have high standards for anything beauty-related, and I think his passion for it and his own looks would attract a lot of customers.