Yes, they need to bring order to their shop. In real shop goods at shelves not messed in dissaray))).
About SS in shop. I dont think they are useless. But they are horrible expensive, though. 40 diamonds for just one soulstone - its natural robbery! I like buying SS but only those, that cost gold. For other SS, i think 10-15 diamonds will be good enough. And SS of Elric and Ember must cost gold, like i suggest before in my post.
Button that you are suggest will be handy. Its always good to not waste accindentally diamonds, because they are costs real money.