Buddy you don't need to draw pentagrams in it, just flip through it. Plenty of creepy stuff all the way through! Look closely at the more detailed pictures. Keep in mind these were painted by hand, by very skilled painters. What you see aren't mistakes. There's a few threads floating on this board from a long time ago talking about these.
Also, that book is chock full of golden JW stumpers. Only the most skilled and knowledgeable JW could sit through a whole weekly study in that book without being completely lost. Even against the most scholarly JW, in a discussion you could have him dancing around making excuses or being confused with some carefully chosen questions about that book.
Id say keep it, with a page of notes in the front of it in case you get a chance for a sit down with a JW in your house.