TrailHead says:
... None of the other specialties listed in the core book seem to fit. ...
Treat them as examples. Make up whatever you think is interesting.
TrailHead says:
... I was picturing him serving in the Army as a mechanic. ...
Then Mechanic makes perfect sense as a Profession. (page 70)
TrailHead says:
... since my character didn’t go to university ...
You didn't go to university as a Pre-Career Education, but you could still have done so on the GI Bill. I am not sure that fits your story so far, but if you want something that looks like it would need education, that means you got the education.
TrailHead says:
... I don’t know if we’re allowed to use Traveller Companion options ...
For this? The book only contains examples, so taking examples and inspiration from other books is fine.
I don't have that book, so I can not comment on anything more than just Example Profession ideas. If it is non-mechanical, use whatever you want.
TrailHead says:
... Interesting. I wasn’t planning on taking another career. Even if I don’t, there’s some backstory there ...
Yeah, the system did not agree with you about not taking another, the system knew it would be short. :)
Even just getting the Qualification Bonus is a story ("I coulda been a ...").
TrailHead says:
Okay, a 1 = no effect. Whew!
Close one, though. :)
TrailHead says:
... implant would be cool but doesn’t fit the story so far ...
No worries. It could
change the story, of course. But END is good.
TrailHead says:
... second roll was 2, which is +1 to INT ...
Army has some really nice Benefits, and their Cash is not great. Good choice. :)
TrailHead says:
... the Mishap table is story gold! ...
Indeed. I have been fretting that no one has rolled any of those. All these Terms and no accidents or medical expenses? Something is up with this crew. :)
TrailHead says:
... It feels like I just got to this planet ...
Yes. What did you
do?! Army vets come in and things go to hell!
Do they blame you? I think
I blame you... but I can't find the paperwork. :)