Hi Ryan,
The arrow frames aren't really designed as an animation to be played start to finish, but are rather trying to cover as many angles the arrow could be facing during flight. I would select which frame to use depending on the direction of the arrow.
I failed to explain this in the package. Sorry about that.
Here is a demonstration of the angles each frames is roughly trying to cover:
You can pretty decently cover a variety of arcs with these frames, but for straight shots you probably only need frame 3.
I'm not a great programmer by any stretch of the imagination, so it's probably for the best if I didn't give any advice on how to implement this. One thing I can recommend trying is adjusting the anchor points of each frame to the arrow head.