Although I think the keywording on everything is underutilized, and we've had discussions about assigning career keywords to what action cards careers can buy, here's an alternate consideration that might help create more detailed and therefore more unique careers.
Currently, any career can buy any action card as long as it has an advance available, and can pay for it (i.e. Rank 1 buying a Rank 2 for 2 advances), etc.
When I consider that a Negotiator can buy "whirling bladestorm of death" as easily as a hardened Mercenary or Pit Fighter, I start thinking how could this be better represented. What I decided was that the action card advances were simply too broad to really encompass the 'theme' of each career. Granted, there aren't all that may types of action cards (combat/support/spell/blessing), but they could be divided into a couple sub-categories (i.e. any combat card requiring a melee weapon is a 'melee action card') and then the action card advances for each career assigned allowed categories.
At creation, players are free to choose whatever action cards they want. But, once they've set on a career path, they can only buy from the action cards available to that career.
Example: Mercenary gets 2 action card advances, they would be limited to (combat, support), where combat is both melee and ranged combat. Messenger gets 1 action card advance (support).
Action cards that have a character's trained skill and/or one or more matching keywords with the current career could always be purchased. This represents the current career's mindset (keywords) influencing training/decisions, while the trained skills can represent prior knowledge/previous careers.
Example: someone shifts to Messenger after Scout and has Ballistic Skill trained, Messenger would not normally allow a ranged attack action card purchase, but since the character has some training/knowledge of ranged weapons he could expand on that knowledge.
Like I said, there may need to be a little more detail to the categories to keep this fresh and not an exercise in combat type = combat cards, non-combat type = support cards, caster type = spells/blessings.
Just a random thought this morning, any comments?