+1 that NPCs should notice a picked pocket more quickly than a picked chest/body (possibly only after you exit and re-enter the area?).
But I'd also argue for hearing radii around NPCs instead of just sight cones and/or additional guards/locks on the chests full of more valuable loot -> make the process of stealing a bit more difficult, but you're more likely to cleanly get away with it upon success.
If there are going to eventually be bookshops in the game, then it makes sense to be unable to read red-symbol books. But honestly this could just as easily be solved by any book vendor only having readable books in their wares, not lying around in the shop.
