Personally ive found that BLM fits this description. You get a primary aoe ability at an early level in fire 2(level 18), so you have plenty of time to get used to it and eventually learn how to weave your other aoe spells(thunder 2/4, flare and now foul) around it. As a bonus, you have an aoe sleep for emergencies. You also have a strong single target rotation that is easy to learn, but with enough nuances that it takes an effort to completely master. BLM are considered to be near the top in both single and multi target damage(this can change as abilities are patched). The downside? You are a caster, so you arent as strong as a melee character when under direct assault. Basically all your moves have a casting time, with all the problems that can cause(having to move interupting a cast, enemies dying before your cast finishes meaning you didnt actually do anything, fights with a lot of movement making it significantly harder for you to perform at your best, etc). And not everyone enjoys the cannon playstyle(move to spot, repeatedly fire big spells while standing still, move to next spot).

And im not sure what you meant about losing resources, so im not sure if this is helpful. But a well played BLM has infinite mana, so no resources to consider.