flights from Sydney to Amsterdam via Shenzhen and Beijing

This is not the first time we have flown in to and out of Chinese airports but will be the first time flying in as an International passenger then taking a Domestic flight to meet up with a forwarding International flight. I have searched the web and found many articles on 72 hour free transit, Direct Visas and so on but not quite sure what to expect.

The questions I have are related to the flights from Sydney to Amsterdam via Shenzhen and Beijing:

1, Our flight from Sydney to Shenzhen is International when we disembark as International passengers are we required to have a Visa or obtain one at the airport to enter China to then take the Domestic flight from Shenzhen to Beijing on the same day 3 hours later?.

2, Will we be treated as transit passengers or passengers entering China to catch our onward Domestic flight?.

3, Will our luggage be sent to the forwarding flights or are we to collect them from the carousel and proceed through Immigration and customs then check them in back in?.

4, Is one and a half hours enough time to meet the flight to Amsterdam once we land in Beijing on the same day if we need to collect baggage and proceed through Immigration and customs then check back in maybe in a different terminal?.

Flights are:
22/07/17 International Flight 08:45 China Southern CZ3072 Sydney to Shenzhen Landing at 16:45.

22/07/17 Domestic Flight 19:45 China Southern CZ3155 Shenzhen to Beijing landing at 23:00.

23/07/17 International Flight 00:30 China Southern CZ345 Beijing to Amsterdam.
I thank you for your help and support in advance.