far as I'm concerned the pump running once in while is normal, on mine it takes hours if I'm not using the water
I have better more useful things to take apart to 'fix" than to screw around with the FW pump to clean the check valves to stop it from running once every few hours.
Ted do you have an expansion tank in the system? If not only a little water
will drop the pressure and the pump will start more often (sounds like you don't if it only takes a second to repressurize the system).
PS - I have never been on my boat
for weeks with the pump breaker shut without using any water, so I can not say if the pump doesn't run for weeks.