RE: For the tab shooters:
never heard of permanent anatomic changes causing flattening of the fingers from shooting with a tab. The same amount of pressure is applied to the pad on your finger using a glove. The continuous friction over the fingertips can cause the body to respond by producing thicker skin at the site of pressure known as hypertrophy or in other words a callous. This seems more likely to develope using a tab which provides less protection.
Jim