I'm reading through the rulebook, and I noticed two mistakes I didn't find mentioned anywhere on the forums yet (but perhaps I've missed it).
First, on page 15 under the heading Full Actions, it says "you may choose one of these four actions:" then goes on to list three.
Also, on page 21 of the rule book, in the sidebar on Line of Sight, it mentions that the Warlock has no LoS to the Raven, which seems misleading because the Raven is flying (I don't see a guard marker or a Maim Wings attached to it) and so should be in everybody's LoS, if I've read the rules correctly. Perhaps a non-flying creature would be a better choice here, and it might also be good to reinforce the fact about flying creatures in this sidebar.
But all in all, you guys did an amazing job with the rule book! It's very well written and thorough. The sidebars are excellent, and I like the fact that there are examples for pretty much everything. It's a pleasure to read, and does a great job at getting you excited to play the game.
I hope you find these comments helpful.