[ikeboy]

>If an item comes out of its location, you have no idea which seller it comes from.

You can check if the location it was supposed to be in is empty. From my understanding, the main issues happen during receiving; if it's received to the wrong shipment it'll be incorrectly marked in the system and unlikely to be fixed. Once it's received to the correct system everything else is fairly robust.

>If an item is pulled incorrectly, and then set on the return-to-stock pile, you have no idea where to put it.

If it's pulled, then there'd be a record of where it was pulled from, and that place would be empty.