Transfers between servers are always mixed.

With regard to 1, we could reasonably conclude that it wouldn't perform. Transfers to  Burning Crusade Classic Gold full servers without massive queues were not permitted. Even a slight change in racial categories was not enough to convince players. It is widely known that racial differences between arena alliances can be superior, provided that all other elements are equal. This means that Horde PvPers would like to be Horde, which is understandable.

I've said that this is a weak argument because it's not a problem to be avoided. It is possible to block the ability to create new characters on Horde If the server's population is increased to 55/45 Horde preferential. This eliminates the possibility that the server will become massively unbalanced.

The current system is incompatible with the entire premise of the game that has two factions which has been the foundation of Warcraft from the very beginning. Offering free faction change (mind you, they can limit it to one time per account for any number of characters), so people can switch all of their characters would be an ideal solution.

It seems like an easy solution to keep it out of the way to create new characters for horde, however the implications and backdraft could be enormous with plausible arguments such as "I want to play with my buddies" or "I am interested in becoming a horde, because I like orcs."
It is also necessary to limit the creation of Horde characters on any server within the bgpool. This is not feasible, or?

People also had the opportunity to swap short queue times for quite a duration. They didn't. They didn't use the free transfer servers. This doesn't surprise me as most people choose the side they prefer to or with their friends. It's hard to alter this.

"I would like to play with my friends" is an argument that is not very convincing for not having balanced servers or Bg pools. Faction change would allow them to join with their friends in alliances instead of playing in horde.

Transfers between servers are always mixed. You don't know for sure if the targeted realm is as good as the previous one. It does not matter if there's no queue, it could be a shambles, if there isn't a dead world. I experienced that  cheap WOW TBC Gold first hand in Vanilla, where our guild moved to a brand new server and within 2-3 months, the population dwindled to a few hundred players during time of peak.