Patrick,
I'd start with the grip first, low wrist, peak of grip into the lifeline of the hand, squeezing a little harder with the bottom fingers. Just like you would grip a pistol... From there I always go to braceheight....starting around 5 3/4 and go up 1/8" at a time. Some of these Hill bows like 6 1/2 - 7".
If you've tried all those different nocking points and the arrows are still kicking, it's almost a sure sign that the limbs aren't recoiling at the same timing....your bow limb timing is off. Both limbs must return to braceheight at the same time. Because your bottom limb is shorter than the top limb, it must be bent further to compensate, so it can return in the same timing as the top limb. Grip pressure is critical with a low wrist to accomplish this. Line up the belly of the grip with the Y between your thumb and first finger...the back of the bow should line up with the finger pads between your first and second knuckles...now squeeze your fingers with pressure not on the fingertips, but on those finger pads (like you do when you shake someone's hand). This seats the bow grip into the hand, giving you control and helping the bottom limb to bend correctly. Now try shooting with the bottom of the nock about 1/4" over 90 degrees....