Passport not valid for 6m beyond departure date -Transit through Guanghzou on 24-hour stay permit?

Hi, I will be travelling from Perth, Australia to LA, USA in April 2014 for holidays with a passport which is only valid until Sep 14, so less than 6 months beyond my stay in the US. We are transiting through Guanghzou on China Southern and have follwoing query:
1.Am I eligible for the 24-hour stay permit?
2.Will they let me travel on considering that the US and Asutralia have confirmed they do not require my passport to be valid for another 6 months beyond departure date or entry date.
ate. Can I exit an re-enter the airport or do I need to remain at the airport during the layover?
3. Anyone have Border security contact number at Guangzhou airport?
Thank you in advance :)