Bear with me as this could be long winded but I believe you could Agree or even possible think of these ideas yourself.

Firstly: The Guild Hall - Many in the Spiral knights community have Guilds. Guild come with a Guild Hall except, it's kind of pointless and under used. The max amount of players in a Guild is 100 right? How about each time your Guild gains 10 members the Guild hall upgraded. By the time you got to 100 members you could have different rooms. Stalls that are exclusive to players in Guilds (Accessorizes for players who have 20/30/40members/etc.)
The Guild hall too by the time you get too 100 members is all done up, posh, shiny. Maybe a big fountain? The possibilities are endless.

Secondly: A notice board - This is Vital! Seriously I'm not sure how badly this is needed but it is. A lot. If you need to set anything up in the Guild you will know its a nightmare to do, also you could have items that other members may need. It could be simple. Anyone can post something on the Notice board and it works just like a forum would. Any spamming by a certain member they can be banned from using it. Guild masters/Officers can remove un-wanted posts or even sticky some. The notice board should appear on the Screen like as your mail does. This could be very useful.

Thirdly: Guild Masters board - Same as a notice board except only Guild masters can post on it. This could be for competitions or simple just a thread with the Guild rules on it. (Which would be alot more simple that posting them to every member who joins!)

Thirdly: Ranks - I don't feel as though there are enough ranks. But and more importantly I feel as though the Veterans are pointless. Veterans Should be able to add members. (Not demote/promote just add.) They should also be able to use a new chat like /V where Veterans/Officers/Guild Masters can see it. Just seems like they don't have a purpose and they need one.

Just a few at this time but I'm sure I have forgotten a lot. Please give your opinions :)

Strypey of Sacred.