Hey Fish and chips,
Dont give up. I am sure Cathay do not put much emphasis on your family background. I can tell you my story. I am a local hk guy, grow up from a poor fmaily, have lived my life in the working class for 24 years. I wasnt treated differently to the other guys who have houses at mid level. They judge you on your performance, past experience and your VISION ( i dont mean your eyesight
)
It's really important to know yourself, be well prepared and confident. Show them improvement and how hard you have worked to prepare yourself, not only for the interview but also for your life long career as a pilot.
Let them know you dont come to try your luck, but to show them you are well prepared to take up the challenge.
You can see that my english isnt good neither, i would say to be confident in what you say is more important when you do the interview. Read more than you should know in PPL. Pay attention to the aviation business, know their company expansion and news.
Show them your passion, professionalism and dedication.
At the end, it's a very competitive selection, dont feel sad if you are not selected. At the same time i am also telling myself not to be disappointeed, as i am also waiitng for their reply. Just do your best. It means nothing even if u or me are not selected, i can just tell myself i am not suitable at the moment, but i m not kicked because i am bad.
All the best!