If you took off a lot of metal from one blade and almost none from another than yes, it is now out of balance. If you run it I’m sure you will chew up your cutlass bearing or your stuffing box. Send it to Hale Propeller in Old Saybrook CT. They will balance it to your motor/transmission combination. In the future you might want to consider something WAY less abrasive such as emery paper or 120 grit sand paper.