Planter, you asked about down range velocity and energy, correct?

I don;t know if this was answered in here somewhere, but initial energy is not the same and the only way to get the other would be to know how fast the bolt slows down as it travels. The easiest way would be to set up a chronograph at measured distances and get your velocity that way. Even bullets from firearms are and averageamount comparing ballistic coefficients for speed loss (deceleration) for a type of projectile. And that is affected by air density, wind, humidity, etc and I don;t know of any standard from anyone that will let you calculate that for a specific bolt, head, fletch, etc so to find your energy atX yards downrange you will need the chronograph.
The formula for Ek, kenetic energy is all you need for energy calculation once you have your wiegth and velocity at a set distance.