I've been reading through and mostly what I see is people asking to remove the GC restriction so I apologize if someone has already suggested this and I missed it.
Instead of forcing players to be allied to one GC or another for PvP, allow players with premade groups to pick a GC to fight for, simply by changing the party leader. If the leader is Maelstrom, then the entire group goes to Maelstrom, even if every other member is in another GC.
