Flight Transit - From Auckland(NZ) to Karachi(PAK)

I want to know about the Policy for the Pakistani Passport Holders living in NZ and Travelling to Pakistan via China Air and have Transit time of around 14 Hrs in Beijing and then to Pakistan.

1. Is any VISA required for this Stay at Airport ?
2. If need to Go out, on Arrival Visa will be Granted on Airport and what is the requirement and Charges?

Regards
Syed