A beautiful city in China. People mostly have the wrong image of it though.
No, Chinese people here don't work on rice fields, they are majorly in Finance and Banking.
The Hong Kong Sing Along is when a man is having sex with a woman, and as she is screaming in pleasure he mimics everything that she says(or screams ) in her own voice, thus, in essence, singing along with her.
Even if Hongkongers and mainland Chinese share same ethnicity, they are usually distinguished in large context. For example, Hongkongers are not ruled by Chinese Communist Party but have their own government separated from Beijing. Hongkongers may feel awkward if they are just referred to as 'Chinese' rather than 'Hong Kong Chinese' or 'Hongkongers'.