The PK1A will work great with that pump. And if you have never had a flow inducer in all that time you don't need one now.
The low pressure cut off switch cuts the pump off if the pressure gets too low. The pressure relief valve in the PK1A dumps water if the pressure gets too high. They do different things. The Cycle Sensor would protect the pump from running dry, which does a better job than a low pressure switch.