Choke, Rasp and Shock do damage over time, but more importantly it will take down a type of stat for the target. (STR,AGI etc) So while you may not need all, you might as well get Bio, Shock, Choke and Burn. That way for melees you have Bio and Choke to take down ATK and VIT, and for casters take down MND and INT.
As for Sleep it seems to be the same as it always has been in the Final Fantasy games I've played. Its useless. It is ok for Sleeping sh*t that is easy, but if you are in a real fight in a group and try to use it, all its good for is getting sh*t agroed on you and getting your ass kicked.