Originally Posted by
Zaft
As others said, MRD is going to be easier than PLD for learning to tank. Overpower can be used far more often than Flash and the resource it uses (TP) regenerates quickly on its own, so you don't need to weave in Riot Blades to regenerate your MP.
For DPS, if you're looking to do melee, both DRG and MNK are relatively easy in the beginning. I would say MNK is easier simply because it FORCES you to use specific abilities (due to buff uptime and stance rotation), which means there's less thinking involved. I'm in Opo Stance? Well I can either Bootshine or Dragon Kick. Is there another MNK keeping Dragon Kick up? Use Bootshine for extra damage. Don't have another MNK keeping Dragon Kick up? Use Dragon Kick for the debuff. That's it.