Don't forget all the money you'll need to travel to each of those places when you want/need to move between them. Since you'll have 13 properties and you're 30 years old out of 74-80 year average considering either man or woman, you'll need to set up some pretty serious streams of revenue within the next couple of years in multiple countries. I assume you'll use each of the properties when you're not using them for others to live and generate rent or some equivalent to a utilization cost that goes directly to you. So there is somewhat self-actualization to this plan, but you'll need the actual purchasing power and credit to move on it.
I'm curious where the point lies though. With such a shift for economic earning, it hardly seems viable to lock yourself into 12 other places of living outside what you would consider "home". I get the idea of sort of "owning" a place in each city that has a severe worth of cultural, social, economic meaning, but you're not Jason Bourne, so I hardly see the real function in this endeavor. Though, that's just me. You probably see a more permanent investment in living than in simply cash that's being constantly printed. Housing is more of a objective entity that could entice more social interactions and therefore future clients if you get into owning more properties in the 13 areas you purchase a single place in. Whatever your reason(s), be wise and do avid research into the areas and developments you purchase. And be aggressive with what companies you deal with.
Good luck with your plans.