

My Route Work for 72 hour Visa or possible for the longer visa?
Hi. I am traveling with my wife from Mexico and want to stop in Beijing. Our plan is to stop over for hopefully 72 hours without having to apply for a visa. I would get there via China Southern flight from Japan to Beijing PKX on May 25 at 12:10am (midnight). The idea would be to depart Beijing at PEK airport on a flight heaving to Southeast Asia and leaving on May 28 at 12:35am. I realize that my stay would be 25 minutes longer than 72 hours, I wonder if that may be a problem? I was hoping that because I would've crossed Immigration at the airport by the time the 72 hours were up and that I would be fine, but I don't know if Chinese immigration might say I am not eligible for the Visa because my stay in China is 72 hours + 25 minutes.
Other couple questions.
1. Is arriving at midnight okay? I've heard that it can be not recommended due to the 72 hour Visa office operating hours?
2. Is arriving at PKX and leaving from PEK (different Beijing airports) allowed with this Visa?
3. Are foreign airlines allowed, or do only Chinese airlines work? My inbound flight would be a Chinese airline, but outbound will likely be a foreign one.
Thank you very very much!