Kick from Game Etiquette

At what point should one Kick From Game players that signed up to join a pickup game but didn't actually play? The system requires you have at least two open spots to post the game as Looking For Players. I have some players that joined previous sessions and some that have never joined.  I could just increase the number of Total Players Needed in the listing, but that may give the impression that we have a very large number of players playing, which is not the case. Any community norms for when you should Kick From Games?

The only norms are those you establish for your game. In your case, I'd kick every player that never joined, and also those that joined but didnt play during a session. If you interacted with any of these people, you might want to send a message to explain and that they can rejoin if they want to play, but just explain you like to keep the players list to those who are actually playing.