Server Selection?

Good day! I've created three accounts here, but I seemed to have completely missed where server selection was an option. The three accounts appear to be on completely different servers that I had no real way of choosing. I can certainly limit myself to playing on a single account, but I'm left wondering where this option was when I created the accounts.

I see that there is a Transnational Relocation item that sells in the Alliance Shop for a lowly 810000 coins. Is that the only option that exists for choosing a server? And are the servers here the same thing as what are being referred to as kingdoms?

Not entirely related to the questions about server selection, I'm also a bit curious as to how some players are able to freely move between alliances during this event. The alliance selection was rather lacking here, or at least my knowledge of how to efficiently view the list of alliances on a server. Two of my accounts are in rather dead alliances that don't appear to have the same options available to freely move in and out during this event. How is this sort of thing being done by many players?