well the dagger requirement was for the class invisible knife, as long as you're wielding daggers you make fients as free actions.
Armed with daggers you'd have your intelligence bonus, up to 5 added to your Ac, sacrfice 1 d6 of your sneak attack to deal a bleeding wound, the free action of a fient, and the ability to take 10 on the feint in the middle of combat, So they'd have to make a sensemotive verse 30+char mod if you maxed it out and didn't get any buff enhancing items, then you'd deal 3d6+rogue sneak attack +1d4. Massive damage for a rogue. Sneak attacking with two weapons would put you above fighter damage levels.
course, I'm just giving ideas. lol.