I haven't played anything but the duelist for weeks. Kinda dread hitting 200 cunning but leaving my rogues at level 20 sounds fun. I think I've tried every possible combination of gear. What really made her shine was adding armor penetration... 18 each on my daggers and one superb ring=56 armor pen. Enhanced ambush ring and cooldown amulet= 5.5 sec cooldown on ambush=god mode. Because of her passive that adds 50 crit dmg, you can afford to go for some armor penetration, cooldown reduction, etc on your gear, creating one of the most diverse toons available in DAMP.
Ambush, Swashbuckle, Flashing Steel, Bolt
Combo- Bolt, Ambush, Swashbuckle, Bolt, Flashing Steel, Swashbuckle, slight delay, rinse and repeat. After you blow your cooldowns, begin backing away while bolting. As soon as Ambush cools down, use it to get back in the melee.
I've busted the bubble of several leaderboarders lately when I outscored them. I've never given much attention to the scoreboard but it's fun to hear "You must have had the glitch, to beat me." Nope, just better than you. Actually, it's the support xp from taunting every ~5 seconds with Ambush but shhhhhh!
The best off-hand dagger is definitely Audacity but I don't use it. With Bloody Bargain my survivability is much higher. Been running no barrier NM's lately with very little trouble.
If you have a reliable Saarebas, swap out Bloody Bargain for Audacity. The Duelist can get 10k+ out of the Audacity explosions.
Since you want to dump your elusive before it gets taken away, Bloody Bargain's attack speed makes your animations go faster, enabling you to unload that elusive more quickly.
Try to keep two of each BB and Audacity. Armor penetration isn't very good on threatening and perilous so you'll want 11% attack for those difficulties.
Short video example of what she can do with this setup. I only have 77 constitution so I chug a lot of pots. Finished this one with no deaths despite the level 5 assassin in the fade.