During the swing, my right hand (right handed) tends to open off of the grip during the back swing (my palm tends to open up on the back swing uncovering the thumb of my left hand). Is that correct or is that a flaw? How do I fix?
It is a flaw and will lead to pushes and or hooks. Keep pressure with the heel of the right hand against the left thumb. Try in practice, placing a small twig or stiff blade of grass in the space between your right palm and left thumb, right at the intersection on the left thumb and your bottom of your life line near the heel of your right palm. Keep pressure there through out the swing and see if you can keep the twig/straw in that spot and not have it drop out.