you cant protect from everything but installing a undergound 4 inch
schedule 40 pipe is better than a back up pump system. havent known of
gravity to fail yet.

I suggest you leave the existing pump in place, think of the pump as
the back up to the gravity drain.

where does the pump send the water?

another advantage to gravity drain if your in a high radon area the gas
heavier than air should flow towards the open drain location