RE: Right handers shooting lefty
My son is right handed shooting left handed, and for him the change made a significant improvement in his shooting. He was always leaning over with his head to look through the peep. He could not close his left alone and leave his right open, but could do it the opposite way. As a kid, he batted left handed also, so I thought it the transition would be relatively easy. It took him some time to adjust, but he enjoys it a lot better.
My wife just started shooting and found she was left eye dominate and right handed. She made the switch does pretty good. She doesn't practice very much and really to do it more if she wants to do any 3D shoots next year with us.