When a player is listed as inactive, it means he hasn't logged into the game in three days.
The chat window does minimise, clicking the little tab on the bottom left of the screen should bring it back.
A game admin can remove a player, but that player has to have become inactive first. If the player was removed, then his name wouldn't appear as controlling the nation, just the default/stock name for the national leader.
Also moving this thread to the Questions and Answers section