Agreed, same here. SPOILER The consensus seems to be that 8 has more than one answer, I definitely see 8A as different from the others (arrows pointing away from each other as opposed to perpendicular), but perhaps there is another one. Brain is too tired to figure out another possibility right now; thanks for the workout :)

BTW #6 I found most difficult (even more so than #9), and #7 was far too easy for its position.

TO AUTHOR: The answer key for #6 is wrong. It should be A, not C. (The boxes are on the LHS of the frontmost arrow in A; they are on the RHS of the other three.)