If you want a control rogue focused around debuffs, start with the Shadowblade preset. You can pick up a second knife if you wish before trouble starts on the boat. If you later find that the damage loss from going single-handed does not outweigh the benefit from sucker punch you can always switch to dual-wielding later.
For control you want at least the Rogue skills Chloroform, Gag Order, Rupture Tendons, Cloak and Dagger, Sawtooth Blade, and there are others as well. You probably also want to take Polymorpher 2 for Chameleon Cloak, Chicken Claw, Medusa Head, Spider Legs, and Spread your Wings.
In terms of Elemental Schools, Aero offers a few things, like Netherswap, Teleport, and Blinding Radiance, and maybe even Evasive Aura for dodging. You want high mobility to get around the battlefield, so I would take Huntsman 1 for Duck Duck Goose so you don't have to burn precious Movement skills to get close to enemies, and it also lets you take First Aid to help clear statuses which land on you.