I don't know if they would let us choose pets if they added Beastmaster. SE thus far has shown us they prefer every Job they add to be extremely structured with absolutely no customization aside from visuals. Hence, if we actually did get a beastmaster class I have this growing suspicion it wouldn't tame beasts so much as some kind feral spirit beast kind of creatures with it's attacks.

Now if they DID add it as an actual pet class, for one it would probably have the type of creature we use already selected from the beginning, secondly I'd want all of the oGCD abilities by the class to be done by the pet to emphasize the concept of the two working together as a pair to inflict damage. Also, before someone says "well what if the pet dies? The class loses it's effectiveness." That's absolutely true and a perfectly acceptable weakness. If you're going to be a Beastmaster, you should absolutely care about your pet and it's wellbeing and managing it's HP and keeping it alive should be part of the gameplay, not a reason to not have a pet reliant class at all.