You cant swap servers freely and keep your character or progression. My friend who picked us east and played for a while needs to fully reset to play with me or vice versa.
Global progression should be a #1 priority and updating a global database with progression to a server should be implemented as soon as possible. So many people asking where their loot is only because they're on a different server.
But you cant queue with your friends in eu if youre us east.
Its honestly kind of absurd, and should be one of the #1 priorities.