Have done several of these in a grp with 3 rogues only (3 is the min you can have to do a mission) and it works quite well with the rogue hide and sneak abilities. You can however get reward at less than 45 plundered treasure. I have gotten it with only the 30 required for experience. However I think you can only get the aug drop with 45+. As far as the rogue "whirlind" ability, I totally agree that it is crap :)
Balgar Battlerager/68 war on the drinal server<drinal Crusaders>
This NPC gives the Poisoned Flounder instanced zone DoD mission. You become a pirate (Enchanter, Warrior, Cleric or Rogue) and have to kill East Freeport mobs for plundered treasure, as well as loot it from chests. You've got 45 minutes. 30 treasures give you experience for the mission, and 45+ give a reward (a nice pair of boots for chain classes, or a +8 to 3 Saves augment). Very easy with a competant group who knows how to mez, assist and pull. Not good when grouped with an idiot who hits sleepy mobs or ***** around with that retarded Rogue "whirlwind" ability crap that Rogues have in it.