A player's combat skills (Ranged: Heavy, Ranged: Light, Melee, and Brawl) are likely to be one of the most used and rolled skills on his sheet. However, only the Bounty Hunter and Hired Gun get these skills as Career Skills. All other career skills have to pay a premium to buy-out-of-career skills.
I believe no player enjoys being useless in the combat portions of the game that will come up reasonably often. Princess Leia and Padme both encountered combat as nobility and ambassadors. Combat is part of the lives of the heroes of Star Wars.
With this said, I think all careers should gain access to "Ranged: Light" (or some other combat skill) as a career skill. The true combat careers, Hired Gun and Bounty Hunter, can differentiate themselves via their specialization trees that are sure to include combat talents where the others won't. I believe without this change Explorers, Colonists, Smugglers (aside from Scoundrels,) and Technicians will feel obligated to buy a combat skill at the premium cost and thus be at an experience disadvantage compared to Hired Guns and Bounty Hunters.
Granted, I haven't had an opportunity to play this with my players, yet, but they all made mention of those Careers being unable to defend themselves.
An interesting suggestion one of my players had was a Talent available to the non-combat careers that allowed them to use one of their other skills in place of a combat skill, but for a very small subset of weapons (Such as Skullduggery for small hold-out blasters, Survival for Slug Throwers, or Deceit for Knives.)
Just spittballing there.