Yeah, initially I wanted to allow players to somehow clear slots, possibly through looting when at full health. But I cut that because of time. Definitely would be a good improvement!
As for the buttons, it was a bit incidental, initially I was thinking way more "hack-and-slash" and less "puzzle", and you would be able to for example Loot a living enemy to pickpocket, or attack NPCs. It is very much vestigial from that idea.