Honestly, I'd revamp the entire class into something like this:

Hrmm…how would I change the duelist…

Change pre-reqs:

Skills: Tumble 5, Bluff 3, Balance 3.
Feats: Dodge, Weapon Finesse
BAB: +5

Allow Class Features to function in light armor.

Level 1: Leave Canny Defense as is.
NEW CLASS FEATURE: Duelist’s Focus. The target of your Dodge feat is the opponent you are choosing to focus on. As long as you using a one-handed weapon and your other hand is not holding anything, you gain an additional +1 Dodge bonus to AC on top of your Dodge feat’s AC bonus and execute a Precise Strike against this target. Precise Strike deals an extra 1d6 of precision damage with your attacks against this target as long as it remains the target of your Dodge feat. Precise Strike counts as Sneak Attack when qualifying for Sneak Attack based feats or prerequisites.

Level 2: Improved Reaction +2, Improved Feint as a bonus feat

Level 3: Grant Mobility as a Bonus Feat, Grace +2

Level 4: Duelists Focus +2 AC/2d6

Level 5: Elaborate Parry
NEW CLASS FEATURE: Duelist’s Challenge: If the target of your Dodge feat makes a melee attack against a target other than yourself, it grants you an opportunity attack as long you are wielding a one handed weapon with one hand free. This feature can only be triggered once per round and cannot grant you more opportunity attacks than you are entitled to.

Level 6: Grant Einhander as a bonus feat, even if the Duelist does not meat the prerequisites.

Level 7: Duelist’s Focus +3 AC/3d6, Acrobatic Charge

Level 8: Improved Reaction +4, Deflect Arrows

Level 9: New Class Feature: Signature Strike: If the target of your Dodge feat missed you with a melee attack since your last turn and you strike him with a precise strike this turn, make an intimidate check as a swift action after your attack lands. If the check is successful, the opponent is shaken for the rest of the encounter as you carve your initials/symbol/favorite picture into him or his clothing.

Level 10: Duelist’s Focus +4 AC/4d6