Why not give out XP for those things?
You can ask the player, "What does your character want?" Then give them a bunch of XP when they do that or accomplish something related to that. If you wanted to emphasize inner conflict, you could award XP if they choose to do the opposite, something that moves them away from their goal.
I think XP works best when it's reinforcing what you already want to do. It's not a carrot driving behaviour, it's the cherry on top of the cake.
Because how would you weigh the XP? One player tracks and kills a thief, the other practises his oratory skills, the third seduces a noble and the fourth frames a guard captain for a crime. Who gets how much XP?
I do not want to weigh those actions, nor do I want to judge what is more fun for the players and "encourage" them accordingly. They know what is fun for them.