bbl,
You're right, there is a lot of uncertainty associated with this profession and industry, and it's nice to see that you're not discouraged by it at all. My suggestion is to consider all options and always plan for the worse and anticipate the worse case scenario. Best of luck to you whatever path you take!
From your other replies to the others, I think i might have some answers to your questions. In Canada, we don't really get a "frozen ATPL" like in many countries. For the purpose of converting a license, a lot of airlines in Asia (Hong Kong included) like to see a frozen ATPL (ground examinations for the ATPL completed). However, in Canada, unless you are enrolled in one of the few "integrated" programs approved by Transport Canada, you are not allowed to write the ATPL written exams unless you have half of the total hour requirement. This means you need half of the 1500 hours for the ATPL in order to write the written examinations for the ATPL (this is where the 750 hours comes from). I hope this helps.
I actually applied to Dragonair's pre-qualified cadet program a while ago and although I have more than 250 hours, they wanted all ATPL written examinations completed, which I was unable to do until I reach 750 hours total time. They said it is a Hong Kong Civil Aviation Department requirement for license conversion that I have passes in all ATPL exams, so until I have those completed I was not eligible to continue in the selection process.
So although having an HK ID gives you a slight advantage in the eyes of airlines in HK, a lot of times they're looking for something more (ATPL written exams completed, jet time, more than 250 hours, etc). From what I see, there are more and more HK people training overseas to get their licenses and trying for the CX cadet programs.
I currently teach at a flight school in Canada, let me know if you have any more questions and hopefully I'll be able to answer some of them.