I don't see as to why the bender would get negative affects just from moving away from the move...
I believe the move is fine as is, if you would have hit Zaheer it would have most likely broke his concentration on making the sphere. The player not moving is due to them being deprived all all their oxygen, instantly draining energy sources. Small movements demonstrated by the Earth Queen such as turning or moving her head and hands is plenty enough considering every ounce of oxygen in her lungs is being pulled out. This way the player can turn and shoot a projectile or blast at the target source. I believe the move requires great concentration, but I do not think that they would gain negative affects. They are close to the opponent because it is a delicate process bending the air out of a humans lungs.
And as Majorite said, the Suffocation 2 works in different ways, give it a try if you have not already.
~Apple<3