4. Mic not listed, therefore it is not the default device (no devices available to select).
Please try to set this:
Go to control panel -> sound -> recording tab
Now click right and check the options called: show hidden devices, show disable devices.
Now all devices would be visible even if they would be hidden or disabled.
Now you could set the mic to default…
By the way: the internal mic belongs to the internal webcam... so test the mic functionality running the webcam software