This post was suggested to me by Facebook and I have to be the most qualified person to reply so I came here to make a comment.
I was born and bred in Hong Kong as a local Cantonese. Lived there for 29 years, studied in local schools including Uni in HK until I moved to the UK just 3 years ago. Since 2018, I started hanging out with expats because my now husband was an expat from the UK living in HK.
I hate the general, day-to-day HK culture. Yes HK people are direct but the directness is not the issue. It only became an issue when people often have all these mean thoughts.
I still am very blunt and direct too but I now choose to not say anything if I have nothing nice to say. This is learnt because it is not in my culture. I also try to criticise less and appreciate more. Lots of HK people simply don't. They hate everything because they live in a very high stress environment.
I visited HK every 6 months ish in the past 3 years. Last time I went back I was 30 weeks pregnant and was wearing bodycon dresses the whole time. I took the MTR 6 times and no one offered me a seat for 30min journeys. People could see the bump but they don't care. In fact, I often read on the HK forum LIHKG and Threads that HK people question why they should give up their seat or help pregnant women when they paid the same bus fare / MTR fare and they weren't the one making the woman pregnant in the first place. They also said "if you are poor and cannot afford to take the taxi to work every day, you should not be having a child" When I told my HK friends that I was not given a seat even once, their replies were "You have been away for too long to remember that you have to stand right in front of the priority seat and ask the person to get up for you!"
Sorry for the rant above but your daughter's HK "friends" are only showing her the unfiltered version of themselves and sadly our HK culture is still rather uncivilised because most of our parents or grandparents weren't raised with class or grace but awfulness because criticism was the tool of choice to improve their children's life and society. Mums would ask "why are you not as good as our neighbours' son in the exam?!" instead of "You have made good effort. Now let's see what you can do to improve next time."
As for the little noise people make for small annoyances, local people do it all the time but it is soooo local that if you are not in the local circle you won't see it. There's even a video from an expat on this: www.instagram.com/reel/DJjPeKLtFQI/?igsh=MjR1cHphd3dhdjl1
All of these things your daughter mentioned are truly local to HK. But if you are in the expats circle in HK, you will never see it because most locals don't mingle with expats. The ones that do are more likely to be professionals and educated so they would have learnt to behave differently.
I would suggest that your daughter find some new friends. Also she needs to know that she can avoid this kind of people easily during her trip. Visiting HK as a tourist is so much fun and she does not need to endure unpleasant people as a tourist.
Some suggestions for her trip -
Hiking: Dragon's back, Sunset Peak, High West of Victoria Peak.
Stream hiking is also very fun if weather permits. Try Double deer. (6 hours)
Beach: sadly not Repulse Bay anymore because now there are hundreds of Mainland Chinese tourists who came on a coach for the day standing around there (making it very very crowded) and sometimes taking pictures of people in bikinis because they seemed to have never seen the beach before
Shopping malls: K11 is really cool!