A Question about leveling

[Anova]

Because of the class system, it is very possible to level every class and job on a single character. Crafters tend to do this a lot to make the most of their class synergies.

In general, the game encourages players to level many classes. You get the xp bonus for any class lower level than your highest level class.

Generally, you will level 3 classes on your way to max level. This is to gain access to useful cross-class abilities and to qualify for advanced jobs that are available starting level 30. Those jobs require a level 30 in your base job and level 15 in a secondary job. Most players ignore the secondary job after reaching level 15, but there are some benefits for specific classes. For example, the ability to cast a spell like raise without cast time or to instantly summon a pet is invaluable.

As an arcanist, I would recommend leveling thaumaturge for swiftcast (no cast time on one spell every minute) and conjurer (protect and stoneskin for additional tankiness). They will also help you unlock your jobs, scholar (healer) and summoner (magic dps).