I turned off what I could in the options (leaderboard notifications), but I still have "x joined the guild" or "x left the guild" popping up in the corner of my screen, and can see no way to shut that off. While that wouldn't be such a big deal (annoying, but tolerable), my game stutters/freezes every. single. time.
Which is once every 5-10 minutes. That IS intolerable and if there's no way to turn this off I'm going to have to go back to being guildless - which is a shame, as I have grown quite fond of my current guild.