Hi,
I have a couple of suggestions regarding the AFK (away from keyboard) feature:
1) If a player is inactive for three or more consecutive turns, then the AFK mode is automatically set for the player. This would allow the game to be enjoyed by others, without holding up - and (unlike kicking), allows the player to continue the current game if they want to.
2) When in AFK mode, perhaps display on screen the keyboard shortcut to turn it off. Not everyone knows about the AFK mode (let alone the keyboard shortcut) - so this might be helpful for some players.
Thanks.