RE: are kill shots really necessary?
I always concentrate on the deer's reaction to my shot as much or more than the arrow which I usually have a hard time seeing. That reaction is but one factor in determining where I have hit and how well. Blood color and the way the animal departs are others.
I STRONGLY recommend John Trout Jr.'s book "Finding Wounded Deer". It is a book not just to read but to study. I also have an use his earlier work "Trailing Whitetails." Though I rarely hunt whitetaisl anymore both these books apply nearly 100% to Milies, Blacktails and Elk.
Bowhunter