Umm, first "wrong" grip is actually right. At least in air rifle shooting. I was an NJROTC cadet last year, and was part of the school air rifle team (got transferred to a new school without an NJROTC program). When standing or kneeling we used our hands as platforms. As for second "wrong," it isn't that bad. If a bomb goes off and you are thrown to the ground and insurgents are coming towards you from the left (or the right if you're left handed), one could, in theory, "hug" their SMG, AR, or shotgun and provide rapid suppressive fire.