I think rogues are pretty much weak until 26 when you get cheapshot. No damage, but 2cp's and 4 second stun isnt too bad for an opener. Rogue's are screwed in duels anyways because you usually dont get a stealthed opener off. As far as armor, just try and get some decent +agi gear and stick with it for a while, my level 18 gear mostly lasted me to level 32, with the exception of some lucky drops that I could use. For weapons, your almost better off with swords or maces at that level, good daggers are REALLY hard to find then. Best you can get then is a pair of pearl handled daggers, until you can do Shadowfang Keep and get Meteor Shard, then Gnomergan for Toxic Revenger. You'll have to be 25+ for SFK and 30+ for Gnomergan.