I just discovered this game a few days ago, and I LOVE it! I'm still on my first play-through, but I do have one suggestion: how about a separate "key" inventory section? I mean, let's face it - you won't sell the keys, and you want them on you at all times, but they take up a lot of space in inventory (especially if you're a pickpocket like I am). So perhaps add a "key" icon in the inventory panel, and clicking on that takes you to a list of all of your keys.
Thoughts?
Keep up the great work!