BLM

[Vindicate]

Is it worth socketing +crit rate materia into the gear? For I know, we have one of the lowest crit rates basically, does anyone know if its worth it or just socket determination?

The potency of the Thundercloud Procs is determined about the base hit potency of each Thunder Skill and its over time damage.
Thunder 3 does more initial damage and lasts 3 seconds longer, which is in fact 1 tick, thats where this high potency comes from.
Same for Thunder 2 compared to 1.