If a GL is inactive for 14 days, the leadership will be passing on to the oldest non-GL member.
Daily reward for killing boss is 2x Pattern of Basic Race. This is only given out to the current members of the guild at the time of the first boss kill in the day, and offline members will receive the reward once log on.
If you leave a guild there is a 24 hr cooldown before you may join another. However, if you get expelled from the guild, the 24hr penalty won't apply.