I do not know, pickpocketing is pretty hard to balance in all games. A cooldown could work, although it would not solve the problem, just mask some symptoms. You would just loot a thing or two whenever you enter the hub. You could also change the way traders are positioned, so they do not turn their back to you, or you could add additional NPCs, so you can not sneak as easily. Still an invisibility potion would do the trick and I do not know how expensive or accessible these are. You could increase the amount of checks required to steal something, or make only certain items pickpocketable, small things not halberds. You can make it as hard as you want and there are many easy ways to do it, but then you are also robbing the player of choices and possibilities, which the devs likely want to avoid.
Right now there also aren't any consequences attached to stealing it seems. You just fail and that is it.
The biggest issue with pickpocketing however is unfixable. That is quicksaving and reloading. You will not want to restrict saving in a game that is pretty difficult to start with and that is pretty transparent in it's mechanics.
