I would love it if there was one OP NPC in the game who gave a huge temptation to steal from but would kill anyone who tried.
Yarrow's father... I pick-pocketed him and failed, he flayed me alive.
I will say, one of the things that bothers me the most about the way it currently operates is that if you pickpocket an NPC and get away, the pick-pocketed items are still marked as "Stolen" and other NPC's will take them away if they find them during a search.
NPC's shouldn't inherently know which objects are stolen and confiscate them. Either Put a timer on the "Stolen" flag so that it will eventually go away, or only allow NPC's to find objects that were stolen from them, not from others.