I'm an old-school PC FPS player. It's really annoying to have your "use" key be X when you're using WASD. Much better if you could change it to E. Also, having P = Deck and I = Pets makes no sense. Make P = Pets and make K = Deck, or some other key based upon a player's preference, such as how often they use a particular function.
I'd also like to see a notepad in the backpack options. Several times I found myself going "hey, I want to make a note of where I saw that," like with the History of Magic books. It would be very convenient to have a place in-game to store those kinds of notes.