The rings are 1". The little screw on the speed ring seems to be a friction adj to me, but I don't know for sure. One of my V-zones seemed to have a looser ring than the other two, so I tightened the screw just a tad and it helped. It was loose enough that I was worried it would shift. I do know for a fact that all of your problems show up in spades at 40 and 50.
When I've suspected the breeze was getting me, I've gone so far as to reverse the target and shoot the opposite direction to see if the wind would blow me off target the same, only to other side. It did. Here's 3 at 50 w/ Emax w/ some light breeze. The black is 3". I was using the 50 yd aim point, and could have done better using xhair, but wanted hunting type situation.