You should discharge the water under the water below the float. This way you aren't rocking the float.
You should also consider some type of timer system along with a Cycle Sensor or Pumptec to protect the motor. You will have to run the pump until it has almost exhausted the well then have the timer shut it off for a long enough time to let the well recover before turning the pump on again. Once you get the tank full, it should be pretty automatic after that.