There has been a lot posted on communications, all well and good.
But guild administration is another item.
1) Last date and time on-line would be very helpful for determining who the inactive players are. As things stand now, you have to guess who you have seen online, or kick blindly, to make space for any new members.
2) Broadcast guild mail - since there is no guild notice or announcements page, a guild wide mail option or the like would help in communicating with all guild members that are not on-line frequently. Ideally a forum for guilds would be nice, in order to be able to store information and ideas, but administering this may be beyond current scope.
Of the 2 above, last date and time online would be the best information to have and likely not be that hard to arrange.
Capellaa
both have been suggested in a way