RE: Fine tuning ?
I don't think it's a BOW issue. I would suspect more that it's an arrow spine issue. You don't say what spined arrow you are trying to tune, but I'll bet your arrows are underspined. Now, instead of going out and buying new arrows you just might try turning the weight down on the bow about 5# and see if you can get them to tune better.
And for tuning you should get the arrows flying good in the vertical plane before messing with the horizontal.This means to adjust the nocking point first. And as for horizontal adjustments? Read the bottom of page 8 in the tuning guide---"release shooters may get the opposite indication from the norm".