In the end good fine tuning, getting an arrow that is dead straight when bareshafting, is about having lots of arrows, lots of inserts, lots of points, and absolutely consistent form, shooting in a controlled environment with all the necessary tools available...I do my fine tuning in a friend's basement that I call his test lab...he sells arrows and has been making arrows for a long time...I have bought more than 500 dollars worth of arrows from him in the last year...in the end arrow tuning for me was all about finding the right person to do it with...remember that before I found him I was in pretty much the same situation you are
DDave