Back stab only works with daggers. But its mighty awesome. why would ya get rid of it, I know it has little damage but it has the highest attack speed of most weapons, and if you have a dagger with poison or freeze it works wonders.
I just hate daggers. My goal in the game is to make a Paladin type character with a big 2 hand hammer (even though they seem like they suck) and some healing skills.