The small plastic pins that are sheared off now were just there for the original assembly at the car plant. It's a telescoping shaft, and the plastic pins helped hold the length of the shaft assembly, so it wouldn't separate or fall apart during shipping or assembly when installed into the car at the plant.

As most of us know and probably obvious (but it wasn't mentioned yet), it's a telescoping shaft, a safety feature, during a frontal impact accident, the shaft will collapse and it won't push the steering wheel into your chest cavity. Whatever you do, don't weld the shafts together, it's intended to be a slip fit joint and lining it back up to the original location with the correct shafts for your steering setup is ideal.