Better minds than mine will be along, but grouping is not the only thing to consider. Are the arrows hitting straight? If they are not Porpoising, or Fishtailing in flight, then Nock orientation will tell you how they are flying. Nock right or Nock left.
If I was you, I wouldn't worry about perfection at this point. I assume you won't be hunting anything for awhile, so perfect arrow flight isn't critical, as long as they aren't flying all over the place of course. Your bow may be very spine tolerant and 50 grains isn't critical, and your form may very likley be inconsistent. Don't overwhelm yourself with details until you're confident your form is correct and consistent. For example, if your anchor is not consistent, say you draw 27" one time, them 26 or 28 the next, it changes the entire draw weight you're pulling. They could show weak one shot, then stiff the next. A good form excercise is to get close to the target so you can't miss it, and close your eyes while drawing, anchor, and release. It's amazing how you are aware of all the details of shooting, when you aren't distracted by your arrow, or where you are hitting the target. I like to shoot in the dark sometimes. I have a tendency to want to flick my eyes back and forth from the target and the tip of the arrow. If I release when I'm looking at the arrow tip, I of course hit way to the right. By shooting in the dark, with a flaslight directed to a spot on the target, my total concentration is on the spot since I can't see the arrow. It feels odd at first, but it focuses the eye and mind.