A. It's “Minecraft Unofficial Japan Users Forum Server”. It's often called “Setuden Saba”, “Forum Saba” or “Forum Server”. “Setuden Saba” is derived the admin ecolight, means “Setuden” in japanese. (“Saba” stands for “server” )

A. He is admin of Minecraft Unofficial Japan Forum and Minecraft Unofficial Japan Forum Multi Server.
When he is active, sometimes player near him dies for no reason.So, please be careful.

A.You can do for free.
The server admin ecolight is kind enough to maintain the server so that a lot of players can play comfortably, but the cost comes high and donation is considerd.