I'm new to the game, liking it a lot so far. It's brilliantly put together, well thought-out and fun!
I just have a couple of questions about assigning keyboard shortcuts to inventory items:

1. Is there a way to unbind an item's previously assigned keyboard shortcut without swapping it for another?

2. Is there a way to check which custom key I have assigned to an item in case I later forget what its shortcut is - In other words, does it display in text anywhere in the game for the player's reference?

I know that this post is kind of old, but I'm new to the game too and had the same questions. From what I've found :

1. Dropping the item unassigns the shortcut, but I don't think there is another way to do this

2. Unfortunately, there is no way to see what Letter or Ctrl+ keys are bound (see this discussion). At first I was confused that only Numbers and Shift + Numbers shortcuts are shown, but you can indeed use any key, provided that they are not already in use as a game command (Options > Controls > Redefine keyboard)