Reducing my level

[Hippo]

Yes I believe it will show GLA as level 1 as you can't choose DRK as a starter job when creating your character.

oh well, guess i will level a gladiator then. Can I level a gladiator to level 70? Or classes can level up to level 50?

[MistakeNot]

oh well, guess i will level a gladiator then. Can I level a gladiator to level 70? Or classes can level up to level 50?

You can get classes all the way to level cap.
After reaching level 30 as Gladiator you will want to pick up the Paladin job. Your Paladin and Gladiator level will always be equal to each other.

If you really, really want your character sheet to show only a single class or job, then you are out of luck:
All classes will want to pick up their corresponding job after reaching level 30. Doing otherwise will severly cripple your character.
The jobs that do not have a base class require that you got some other class/job up to level 50 first.