Pickpocketing appears to have no consequences.
For me pickpocketing is not working: I try to "take all" or just to double click on one object - nothing is happening. But npc notice that I'm trying (and failing) to pickpoket them and attack me.
The few people I've tried to pickpocket have not reacted at all to me failing. Nor has anyone around them.
I don't think you can take all. You have to select the specific item you want to take, then click pickpocket so that you can roll to take that item. Then you do it again for the next one and so on. I stole every magic item out of a merchant's inventory. Eventually I turned the thief invisible because it was annoying having to avoid people seeing, but other than that it was easy and risk free.
