While I think FC is a waste and never truly balances out the game and players should just create a character in the other faction on their own. However, I think there needs to be some consideration as to who is allowed to FC and their reasons why.
The purpose of FC is to balance the game out, not to send characters over to harass and bully other players. So, for a player to choose to FC, one should consider their actions in the game in how they play. Players who have been observed to harass/bully others, not participate in faction activities, and/or having no desire to actually balance out the game should be refused permission to FC. It is of my opinion that players do these things won't change and it doesn't balance the game just because they FC because they have no true intention of balancing out the game. If these players truly wish to balance out the game let them first be observed to care about making sure others enjoy the game not a selfish desire to enjoy making other players hate playing.
Ways to identify that they care about others enjoying the game.
1) they are not seeking out and attacking players repeatedly over and over again that have no desire to fight them or have no ability to atk back like those who are under geared, under level, and are spending their time farming. They also shouldn't be raiding the other factions base to kill players who are AFK.
2) They participate fully in helping the faction kill bosses. They don't hit the boss once or twice and wait for the rest of the faction to kill it.
3) They don't initiate or participate in flame wars in shout, area/general chat, or PMing to mock or also harass players of the other faction.
One last thing is that players who want to have 1 character in both factions and use FC to do it shouldn't be doing it to just reap rewards of the other faction for purely looting the dominating faction, rewards for winning AK and NB, and do it to keep the balance offset to secure victory continuously for their opposing faction.
Such players who have no true desire to balance out the game should be refused approval to FC and they can just create their own characters in the other faction, level it up, and gear it on their own accord and the GMs/GSs shouldn't enable such poor players.