I can't believe this just happened. I had just finished exploring the 1st dungeon, and thought, "I'll get a new sword for level 2!". I went into the store, picked up the sword, thinking I had bought it, and walked out. Where I was almost immediately insta-killed by the store owner. There needs to be a message or pop-up warning you that you haven't bought said item, or that, if you drop the item after leaving the store, the encounter ends and the "Dread Collectors" don't murder you. Also, I think crafting recipes should say in the space to the left whether or not you are of a sufficient level to craft the item, and the ticks and crosses to show whether you have the item necessary should pertain to each individual item, say one steel ingot, rather than just steel ingots in general. I thought I could craft plate armour, only to discover I didn't have enough ingots, when each one was ticked. It's rather misleading.
I think that second bug/feature was already acknowledged, but in regards to shopping, there is clearly a "Buy" button.
Having looked at the UI screen again, I did notice a buy button... But that begs the question, what is the point of the "pickup" button? Putting a system into place where if you drop the item, Brax and the Dread Collectors leave you alone seems fair; the game is hard enough already!