Any extras you find should be a reward in itself (items, extra quest, esthetically pleasing scenery) Exploration xp is a horrible idea. It encourages us to run around to every environment we can just to level our character but have absolutely no reason to be there.
A bestiary is neat, but a detailed pokedex that gives xp in this game feels bad. After I fill my pokedex with Lion info, I'll just stealth around every lion I see from now on because they don't give me anything? KISS, like the Torment list. Simple pictures, clever paragraph you read, and never go back to it again.
Giving no killing xp is also a horrible idea. Why not keep the IE guidelines and let the classic feel of the game shine through!? Kill something, grab some xp. You could gradually reduce the xp amount per creature so grinding would be less of an issue.