Hi I want to travel on NZL Pasport from NZL to Guangdong then cross to Hong Kong

As I intend to travel to HK, would I get the 144h free transit for Guangdong? Then I will cross by Metro to HK, possibly for less then one day... Leaving China, for HK, most likely my Transit visa will be gone... Then, I will be coming back to Guangdong, Shenzhen to Fly back to NZL. Would I get then the 5 day VOA for Shenzhen or Guangdong, to fly back to NZL. As far as I know the 5 days VOA is for Shenzhen. I think the Guangzhou Airport is in Shenzhen. Am I correct. Thanks, Stefan