First off thanks for the menus to invite to group and such to the roster. It really is a big help!
There are a couple small issues with the guild menu.
1. You can't see complete message of the day or description from the guild panel. (other than admin edit)
The MOTD shows up in it's complete form as a popup at login.. but in the guild panel it's truncated.
As is the description, which has all of two lines visible.
I suggest either expanding the windows, adding a scroll, or a "view" button/clickable area.
2. Sometimes the guild list is empty or only showing a couple members.
You can fix it in game, but thought it's something to look into.(fix in-game with crtl+u twice)
I also have a couple small suggestions.
The ability to change rank names like "Guildmaster". (this would be really nice)
Show guild rank with name in guild chat.