I think fact of the matter is:
Balance just won't happen. If a something messes up, both sides, one side, doesn't matter : people won't play. You cannot, sadly, force them to play somewhere they're uncomfortable with or for somebody that casts them out. Game becomes unbearable and they quit.
Best way is to try and settle things with people instead of forcing them out. That way balance WILL happen. Other than that - it won't, ever. So it's best to allow people to be on side they wanna be instead of having dead, stagnant account with a player who won't play it anyways. Your numbers will not increase by forced hand. Your numbers will increase by teamwork.
If you want FK side to be balanced - accepting, befriending people is best way to go. Other than that, nothing will change.
And RGs, at least the people from Hookers guild, back out from pvp if numbers are too high. Done it myself multiple times. THAT is the way to balance the game. Not the 'full force stay in this faction because hurr durr' way.
Let people enjoy the game the way they want to, in environment they're comfortable with. : )
P.S. After all, games are for fun. Not for sheer force. ^^