@woodwork:
I appreciate your well-written post. My two-fold answer:
1) A career change is always difficult for the what-ifs and dunno's. But you must, and I emphasize, must look at this particular offer as rationally as you can (I know what it feels like to having to spend a week in front of a spreadsheet while re-reading the "this is your last chance at CX, take it or leave it" -letter). If you've done the number-crunching and conclude the compensation offered is adequate to give you a reasonable means to provide for you and your family, AND adequately offsets the costs associated with a change to expat life right from the get-go, then you'll be ok with it. If not, if there's a slight "but" or an "if", then walk away. I moved away from the EU to the US 15 years ago in search of the golden ticket to airline flying. Now, after 15 years, I'm still doubtful if it is/was all worth it. I hope after your decision you won't have to look back and have to second-guess your call (don't we all...).
2) In the next 2-3 years, most airlines in the world are hitting a brick wall when age 65 retirements start. Not enough new warm bodies to fill the flightdecks; the reason why places like CX et al. are trying to get the cheap labor locked in now and not later. 3 years from now, the tables have been tweaked for the better (no, not completely turned, as pilots are still labor, an as such, we never get to truly dictate our T&C's). You say you are in your late-20's/early-30's. I understand what seniority means in the airline business. But, if I were you, I'd sit back another few years, maybe start working on a PPL/IR and see how this flying thing treats you in a more personal level. Don't go all out and drop a full on loan to a pilot factory, just work on the flying as a hobby. Then, when things start to really heat up on the labor market, you can still go all in, or if not, you've bought yourself a nice little hobby that you can either continue or chalk one up in the life-experience column.