If you happen to get on the Airbus fleet, you will fly a lot more than the B744 SO's. I'm CCQ on A340/A330 and normally do 4 Australian trips per month. This month (December) I have 4 aussie trips and a sim. I dought whether you could commute back to the U.S. on this kind of roster. The 4 trips plus the sim puts me smack on the max hours before overtime kicks in, so it happens regularly.
After each upgrade, SO-FO or FO-CP, you spend the next few months flying regionally (probably not the B744 though) so commuting would be very difficult. I'm not a FO but I gather you would work 4-6 days per week.
Additionally, if you are an FO based in US (pax) and you get your command, unless there is a command slot available, then you'll be stuck in HK until one comes along. This could take a while depending on which fleet/expansion etc.
Fianlly, I believe that if you go into the interview with a mindset of not wanting to live in HK you wouldn't get the job anyway. They ask a lot of questions during the 2nd round regarding what you'll do in your time off, and more importantly, what will your wife do if she doesn't work. HK is not for everybody and you should come here for a visit and see what you think. The polution is really quite bad. ANY dought in their mind and they won't go for you.
Good Luck
WP