But, going back to the OP for a moment, I think it asks the wrong question.
It isn't whether the *game* has room for it - you can, with some thought, create what you like. The question is whether the *genre* has room for it. Or, perhaps more clearly, is such a thing useful in the typical genre for which the rules are used?
That's really what most of the answers seem to be getting at - in an action-adventure game, such a class isn't just isn't terribly useful. You may want some of those diplomatic abilities in play, but they need to be paired with other action-focused abilities or the character will sit in the background contributing little to the game for much of the time. You can have a scholar, or a diplomat, but they probably need to have at least a passing resemblance to how Indiana Jones is a scholar.