Making the player fiddle with his equipment every time he goes to a shop is a little demanding. Perhaps there could be implemented two mods: Battle mode and normal mode. In battle mode the character walks around with weapon in hand and helmet on. In normal mode he stows his weapon and helmet to appear more human. Can't fight in normal mode, obviously. One additional benefit would be that it would be a good way to signal peaceful intent - it shows a person that you're not intending to fight.
Of course, some people would want their helmets at all times because they like looking evil etc, so maybe the player could define whole item sets for the two modes - one with battle rings and full armor and a huge sword and one with charm rings and a friendly smile
