Guild Halls
My guild groups together and organizes without a guild hall. Largely, a guild hall would actually make it harder to coordinate, since it would require one extra zone crossing.
I think GHs would be a fun thing to have in the game and I’m sure it would be convenient for guilds that want to throw a private party, but I don’t see how their absence affects the running of successful guilds.
John Smith: “you should kill monsters, because killing monsters is awesome.”