While I know this is a long way off from implementing with composing and all still to come out, I'm sure something like this could be worth the development time.
In my *humble* opinion one of the biggest issues in this game is the lack of a level cap. This fundamental difference in FS vs other games is, while a defining characteristic, also one of the greatest downfalls in certain aspects of the game. The large level cap at EOC has allowed for a huge disparity between new players and old players, one that a new player can basically NEVER hope to achieve in many years of playing (I've been playing for 5 years and I'm not even half way there, XP wise). This is demotivating in a large sense, and possibly the reason for a low retention rate of new players (as it seems).
We have titans which come close to providing a suitable experience with a level playing field - however, there is a big flaw in that after using stamina to hunt a single (or maybe two) titans, you are left with little that you can do.
What I would like to see is a way to equalize all players across the board, similar to the arena. I'm proposing a revolutionary new aspect of gameplay that is sure to keep people interested 
. Imagine being able to even out the playing field by giving everyone, regardless of level, the same stats, buffs, gear, etc.
Let's implement the classic game of Castle Wars in FS. Every 10 minutes or so a new game starts (for which you can register in the previous 10 minutes), and then you're eligible to play in the next round. Each round begins by auto-dividing players into 2 teams. Players are equipped with special Castle Wars gear with equal stats - gear can be upgraded by playing multiple rounds of castle wars, winning, and performing other things that would qualify as achievements.
The game would be played on a modified version of the world map. Each team gets a "castle", which is basically a giant structure on either side of the realm with some amount of health. Players can attack the opposing team's castle, kill players of the opposing team (forcing them to their own side again). The catch is that the player attacking must be on the same square as the player being attacked. Once attacked, a player is immobilized for say, two seconds. Should a player make it to the other side's castle and begin attacking, they can continue to do so until they are killed. Players can be attacked on either side of the field - though players get a stat bonus on their side which is lost when crossing over to the other team's side. Player HP starts at a certain value every respawn, which is drained through combat.
The various gear players own will determine strategy in this game - "tanks" can have higher stats but slower movement speeds (a longer delay between movement), while "scouts" or something similar can have higher movement speeds but basically 0 stats. Finally normal players can have normal of both.
The endgame is the loss of a castle - the team who causes the opposing teams' castle to fall first wins the round. The players are then forced out of the realm back to the realm they came from, and the new game begins after rewards are handed out. Rewards might include some form of tokens, with which players can customize the gear they own (which is swapped only at the beginning of the game, when registering), as well as various buffs which can be used either in the game or in the actual FS world.
Please post your suggestions as this is a very crude idea and due for some refinement and/or explanation.
