There's a reason why the salary is high in China. And it is not because they like the pilots. You sign a contract and then after signing the negotiation starts. You will earn nowhere near the announced and promised figures. Enjoy the multi resistant infections unless in Shenzen or Shanghai!
In Europe the rosters are bad, no chance of flying long haul except for Norwegian, 15-20 years for upgrade on the majors, crappy salaries since you pay more than half of your salary in tax. If you live in Northern Europe you are taxed even more than that. How are you going to fight your cause if you are not even employed by the company?
Alot has happened in QR since 2009. At the moment I would personally not return to Europe considering the roster and salary.