It is normal for the PCM to wake up when you open the driver door. A self test of the throttle body would not be unusual because it is a safety critical component.
If you want to hear what the throttle body motor sounds like, turn on the ignition (without starting the engine) and press the accel pedal.
As Doctor Drew said, the "clacking" sound does sound like the transmission gear actuators.
I'm not sure why others have indicated the grill shutters as mine do not move until after the engine is started.