RX1: question about 'face detection'

In my quest to understand what's the most reliable way to AF for portraits, I have a question about the face detection feature. Well, two questions actually:

1. Does the face detect specifically focus on the eyes at F2 or is it not that 'sophisticated'? If I use face detect on my RX1, it typically gets the nose most in focus.

2. Can face detect be used in combination with target tracking. If so, how is it done and is there any value in using the combination (I'm thinking if the subject is not completely still).

Thanks