Thanks for all the feedback! You're very right, the books are of very uneven difficulty. One will be full of monsters, another full of loot. I figured "load to library" would be the solution for excessive balance issues but I don't think they ended up too badly.
The backpack inventory is scrollable if you click and drag - a fact that maybe 1% of people figured out if any. I should add a scrollbar. Also auto-equip would be a great addition.