Archanist Question(s)

[Radacci]

Assuming it will be available from launch (it most likely will), the way XIV handles classes means you don't need to do anything to unlock a class, just get yourself the right tool.
Take up a saw, and you can start being a carpenter. Sure, you'll be a TERRIBLE, unexperienced carpenter (a Lv1, in game terms), but it means you are learning the job.

So well, in short, I'm almost sure you can just choose it while creating a character. And if not, grab a Lv1 book as soon as you enter in game.

I'm sure you can pick arcanist at char creation yes.
You could pick up other classes right away in 1.0; but what about now?