Manila to Los Angeles with stopover on Beijing

I am taking Air China on Oct 27, 2014 from MNL-Manila to LAX-LosAngeles with stopover in PEK-Beijing.
1) Can I take a multi-city booking and stay in Beijing for one night and take next day flight to LAX?
2) Can I avail and use the 72 hours visa-free transit?
3) What is the process at the airport?
- Go towards the Immigration counters?
- Go to the Special Lane?
- present my passport?
- how much is the fee at the airport?
4) I want to visit on Tianammen Square on arrival and next day go to Great Wall and then directly to airport, are there tour packages available similar to this?
Thank you. Rico from LA