New batch of ideas!
Guild noticeboard:
A guild noticeboard that stores GM messages, an event planner, daily goals, as well as general information such as who added who, who was removed, who left. There could be reasons provided for all of them, too.
Examples:
"Pirate" left the guild due to "the guild is too inactive"
"Officer" removed "player" due to "troublemaker"
Enhanced form of communication:
There should be some form of communication between online and offline members. Due to timezone differences, many guilds don't last. There should be some chat board or chat history that allows online and offline pirates to communicate. This will also allow players to provide reasons for inactivity before going inactive. Players could perhaps utilize the public-facing APIs and develop some application allowing online and offline pirates to communicate on the go!
Kick rules:
Guildmasters should be able to modify kick rules to their liking. Giving officers the ability to kick others, or taking it from them. They could also set limits or a requirement to state a reason and provide chat logs.
More roles:
As the current roles don't suffice, it would be nice to see more roles in the future. Such as a "co-GM" role, so GMs don't have to worry about being locked out of commanding their guilds as a result of giving others the GM tag in periods of inactivity. There could be a role similar to veteran that allows newer members to recruit others. As they might be unworthy of the 'veteran' tag.
Custom roles can also be created by the GM. This will allow for a more custom guild experience. SvS/PvP/roleplay oriented guilds can create custom ranks with certain powers. I would use this feature to create new roles including a "fleet commander" role for guild fleets.
Color-coded member names:
To make it easier for pirates to notice the ranks of other online members, the colors would look a bit like this:
Guildmaster
Officer
Veteran
Member
Guild statistics:
Statistics such as guild rankings, member increase, member activity, overall rep gain, ships sinked, enemies killed, hours played, and more.
It could also provide a deep look into each and every guildmembers progress and highlight their level increases and activities since they joined the guild.
This could be restricted to GMs/co-GMs/officers. Alternatively, more transparent guilds can share these details with all members.
Overall:
Currently, the guild experience is too two-dimensional and needs severe improvement. Guilds experience short spikes in activity that span over a long time (eg: content updates), so if there is anything else that will enhance the guild experience (eg: official guild activity planners, achievements, etc) it would attract more players to the concept of guilds and may ensure guildmember loyalty.