I think when we or our companions do quests that they should get skill for completing the quest. Lets take escort merchant caravan as example. It requires scouting and leadership so when it is complete who ever ran it should get scouting and leadership exp. It only makes sense. If you do a quest that needs that skill you should get experience for it. It would also help us to level companions in certain areas that are tougher to level like leadership and tactics. I think it would be a welcome addition.