Hi I would like to present a few of my suggestions.

1. PvP Content.

-New PvP Modes-

-Duels (inside and outside the city)
-Arena 1v1
-Castle Siege or some other kind of FC VS FC mode.
Developers mentioned something about that kind of mode, but when can we expect it and how it was supposed to look like.
-Open PvP map

2. Classes
-Two new classes-

-Thief class
I know S-E say something about adding Thief class in future, but mmo without thief/assassin class atm?
-Some Dual wield class

3. Battle system
-Instance/ Boss raids for 20 people, no as alliance but one huge party
-Map or instance where we can fight some of the world bosses and where we need to fight with other teams to get acces to that boss.

4. Other

-Breeding Chocobos?