One thing you didn't consider in your career path is retirement savings. Actual rules vary from country to country, but in general case you should be prepared to lose your supplementary pension rights if you don't stay in one country long enough, even if you had to contribute to retirement insurance there. Example:
Anna worked 4 years for the same employer in country A before moving to country B where she remained definitively.
When she retired, she applied for her supplementary pension from country A, but the insurer refused, arguing that payment was only due to people who stayed in the scheme for over 5 years.
Your plan sounds great as long as you stay young and healthy, but I wouldn't do that "until I'm a sixty-year-old" if I were you. You may end up in a difficult financial and personal situation by that time, unless of course you make enough money to save for your retirement yourself and find a partner who will be ready to share your lifestyle, in which case everything ought to turn out great.
