I was wondering if there ever was an introduction or description of the Beastkeeper world somewhere. Something like what the beasts have in the Beast Codex page. I sort of skimmed through my tutorial quests so I don't remember much from them.

I'm also looking for the lore behind the events' NPC (What are the warlocks, etc.)

There's no one place that has all the Beastkeeper lore but most of it is in various news posts so you might want to check out that section of the forums.

This post happens to include information about the warlocks.