Is this itinerary eligble for 72-hour transit visa?

I'm a Schengen passport holder so I am eligible for the 72 hour transit visa arriving in Guangzhou (CAN). I'd like to travel:
Manila - Hong Kong - Guangzhou on one booking and then Guangzhou - Manila on a separate booking.

Now, my questions are:
1) Technically, I enter from one country (Hong Kong) and leave bound for another (Philippines) but since the first ticket is booked all the way through from the Philippines, does that mean that I can't have that as 3rd country?

2) Would it constitute a problem that the two trips are on separate tickets/bookings and with different airlines?

Thank you!