I don't think that Rogue will use any of those things.
If Rogue got increase drop rate, pretty much everyone who wants relics, would get NIN, just to farm atma/alexandrites.
also there's just a few items in the game, that are semi rare; like puk eggs, pudding flesh. Would be weird if you needed ROG/NIN, to farm those.

But...
Here's official description of Rogues:
"These agile fighters pride themselves on their skills with knives and daggers to make quick work of enemies.

Lurking in the shadows, adhering to no laws but their own, they punish the wicked, pilfering their ill-gotten gains and delivering them to the downtrodden masses. Thought by many to be mere common criminals, some would say they play an unseen hand in maintaining order in the buccaneer's haven of Limsa Lominsa"
So...they might get some pilfer skill...

Ninja:
"Hailing from the war-torn lands of the Far East, the secret arts of the ninja were born of necessity, and have since given rise to a unique breed of highly-trained combatants.

Able to manipulate the vital energies of the land, the air, and living beings, they manifest their power through the weaving of signs, unleashing a wide array of attacks against their foes. Master the arts of the ninja and learn to bend the tide of battle to your will"