Sensorless ESC with sensored motor ?
 

Can you use a Sensored brushless motor with a sensorless controller - just without using the sensor wire ? Is that all you need to do, just leave off the sensor wire.

yeap, as the sensorless ESC uses the motor not the Hall Effect sensor to map the power.

It don't work the other way round though!!!

yes, the sensor circuit in sesored motors is 'extra' to a sensorless brushless motor.