As an ethnic Chinese educated and worked/business overseas I can understand your position better than other posters. This is just major cultural clash with family who has never left China and the different valuation everyone exhibits over goods and services.

• Some will not pay and extra Yuan or walk an extra mile for a better bowl of noodles.
• There is an unwritten Confucian tradition of taking care of younger relatives in your care and make sure no harm comes their way.
• Chinese (most Asians) are very protective of the children; they hover around so much that the term "Helicopter Parenting" was coined. A story of a parents accompanying their university age offspring to China for a summer internship made front page in HK.

If you feel comfortable with the student then I would definitely get Mark out to immerse in the real China. The phone idea is great and there are other methods to keep in touch with him. Seems like he knows what to do when he encounters difficulties.

I have a similar situation: I am dishonouring the family if I don't stay at the "homestead" when I am in HK for business or pleasure.
I am 55+ and my aunt has always been protective of the extended family. When I head out to social/business dinner or evening out she would always: "don't stay out too late, we will worry about you, so don't keep us up all night!" I now stay with close friends for a few days before doing the family visit when I am in HK.
We had to make up an extended family trip to Macau excuse to basically stayed at Hotel on Kowloon side for a few days to give my son and daughter a experience of real night life in HK before LKF.