RE: arrow problems
If I shoot a group of 4 arrows, I tend to have one that goes a bit off course myself. It is nothing to be worried about.
For me it is my focus. Shooting at dots is BORING.
Focus on your form, slow down the pace of your shot and if at all possible, have someone take a picture of you at full draw for 10 or 12 shots. Do the same the next day and compare. Then you will see if you are having form issues.
Also, opening both eyes when shooting helps. [8D]