A lot of war have come and gone in the different Kingdoms, NK being no exception. It is true that we had people move here from HH, but it's also true the other way. This game makes it very hard to protect everyone, so the exchange of people moving between NK and HH is an understandable and frankly expected thing. (The grass is always greener on the other side) Only thing I can recommend you from my own experience so far with the game, stay far away from Akihabara and DiS, you will probably come to regret moving to either of those two kingdoms.
Fire and Ice is a lovely kingdom, with a relatively closed community.
HedgeHugs are big and sprawling with life, and houses a lot of strong people!
While we at Northern Kingdom are.. well frankly, relatively larpy and easy going. o/