Is my copy of Guild Wars 2 tied to my region?
Yes. To play from North America you must purchase a North American copy of the game. To play from Europe you must purchase a European copy of the game. Note that this restriction impacts where you can play from, not which game worlds you can choose to play on.
By purchasing the correct copy of the game, you're supporting the game in your country, and you'll be connecting to your local data center, using your local customer support team, and downloading the correct language support for your country.