was i wrong to use limit breaker?

[Kaurie]

I assume you were using it as dragoon? That, in itself, isnt wrong - but yes, wait until all three bars are filled to use a much more powerful attack.

As a general rule LB should be used in this priority: melee (drg, nin, monk); caster (blm, smn); ranged (brd, mcn). Healers will use it if needed, tanks should never use it (except some special fights). Melee will deal more single target damage than ranged/caster, while the caster-lb is still stronger than the ranged one. And always wait until 3 bars are filled up (2 bars in boss fights in dungeons) or until you can tell that the boss will be dead before you got limit break 3 (aka 15% or less)

Disagree strongly with your general rule.

Caster LB is superior in most dungeons (to clarify, in case you are confused, it's better to do 20000 damage to a pack of mobs than 5000 damage to a boss in terms of speeding up the run). Melee is superior on single target encounters, such as trials and some raids.