I thought the whole point of steppers was that you didn't need feedback, the motor steps one division each time you pulse it - obviously this requires the motor to be more than powerful enough to never miss a step.
As I see it the only way to apply feedback would be to have some kind of sensor on the output of the motor - so you can confirm it's stepped after each step, and if not try stepping again.
You're asking a lot of questions about steppers, what exactly are you trying to do with one?.