Hey,
some of these suggestions aren't mine, just trying to put them all to one thread.

1. Guild Action Logs
This would help Guild Leaders - Some kind of logs where you can see who invited, kicked or promoted someone, currently, you can't see it and if you have few gcs/ges it's hard to know who was the griefer/troller..

2. Guild Leaderboard
There should be some kind of Guild Leaderboard, same as 'Challenge Board', if you wrench it you see top contributors (or all?) of the Guild, Leader can set if it's public (for all peoples) or just for guild members

3. Minimum points to collect Guild Rewards
This is quite simple, Leader can set minimum of points, for example, #17, once member of the guild has over #17 he can collect Guild Rewards, this can help guild leaders alot causing less stress and removing deposit system (in top guilds) - Suggested by QueenChloe

4. XP Leaderboard
Leader of the guild should be able to see how many XPs Guild Members have earned in last week/month, every week/month XP Leaderboard resets (or it might be perma without resetting..)

That's all I can think of right now.
Be sure to leave feedback and excuse my english..
Have a good day,
Cze