Okay, so one of my players wants to add a potential house rule to the game. The idea, on the face, is pretty simple: instead of being limited to the Signature Abilities provided by your Career, you can attach any Signature Ability to a Talent Tree provided by a Specialization of the Ability's default Career, up to the normal limit for Signature Abilities (is there a limit? Can you get both the Signature Abilities listed for a specific Career in that Career's corresponding book?)
As a for instance, and what my player wants to do: His career is Sentinel, with the Shadow Specialization to start, but dipping heavily into Charmer (under Smuggler). Neither of the Sentinel abilities excite him, but the Smuggler abilities do (particularly the one that lets you alter dice rolls, since he's a chronically bad dice roller, and his character worships "The Lady," i.e. Lady Luck, who's name you dare not speak). Going with the Smuggler Career to start means sacrificing the free Force Rating, while going with Sentinel means foregoing the Signature Ability he really wants his character to eventually have.
So, the question I have is, would allowing the attachment of a Signature Ability from another Career, requiring an appropriate Specialization be purchased and filled in enough to actually start buying the Signature, be a horrible mistake?