Is it better to start a new character or just simply change classes?

[Rongway]

I leveled arcanist mainly for healing spell.

BLM will require THM30, and will not require any other classes. No job will have access to the abilities of any other job.

Instead, there are role pools for tank, healer, melee DD, ranged DD, and magical DD. Each role has ten abilities, and BLM will have access to the magical DD actions.