If you make sure the removal tool is under the fasteners, you will not break the door panel. There is no telling what is rattling in the door without opening it, and checking for wear spots, or just shutting it, and watching/listening.
The first place I would look is the screw in the rear of the pocket, that holds the door interior on. Is it loose? Next the actuating rods for the latch, etc. There may be some debris in the bottom of the door as well.