5-hour layover in Beijing on the way to Shanghai for 144 hours

Question 1: We are looking at booking the following trip, and want to know if the 144-hour free policy can be used in Shanghai. The journey to Shanghai involves a 5-hour layover in Beijing, and I want to make sure that this won't invalidate the 144-hour free offer.

Lviv -> Kiev (layover) -> Beijing (5-hour layover) -> Shanghai (144 hours) -> Bangkok

Question 2: The ticket to Shanghai is booked with a different carrier than the ticket continuing from Shanghai. Any problem there?