If there's one thing I learned by playing RDM, it's that some skills feel a little strange. Fleche and Contre Sixte specifically. As attacks, they have their places. However, if they were to be changed to a personal buff that changes the way the sword combo behaves, I feel they would be far more beneficial.

1st change: Fleche
The change I would make here is to change Fleche from a single-target, high damage skill with an acceptable CD to a buff that makes your melee combo into a multi-strike chain combo. Consider this. A 2nd meter that fills up alongside your Balance meter. Let's call it the "Flourish" meter. Every cast of Jolt, Jolt II, Scatter, Impact, Scorch and every use of Reprise, Enchanted Reprise would increase the meter by 5/5/5/5/10/7/15 respectively, capping out at 50 points.

Upon using Fleche, you would gain a multi-strike on sword attacks that change depending on the amount of meter you have. Activation can only be done starting at 20, granting 2 "magical shadow strikes" per skill use that follow the exact motions of your combo skills and deal 25 less potency for each successive shadow strike, with the "shadow strikes" starting at 250 potency. At 50 meter, you would have 5 shadow strikes. Buff lasts for 30s or until the combo is completed. Only affects your main melee combo (both standard and enchanted). So the logic would be as follows:

Meter - 20/30/40/50
Strikes - 2/3/4/5
Potency per strike - 250/225/200/175/150
CD - 35s to 40s

2nd change: Contre Sixte
The change I would make to this is to enhance the range of your melee combo AND grant it limited-range AoE (similar to the range of Moulinet/Enchanted Moulinet). The same rules will apply to the meter, except that it will have 2 parts. One at 25, and the other at 50.

At 25 meter, the melee combo skills will exhibit an AoE quality at 100 potency. At 50, it will be 200. The AoE only affects targets other than your initial target, and only strikes once per skill. The buff is consumed after 30s or when the melee combo is completed. Rules as follows:

Meter - 25/50
Strikes - 1/1 (AoE)
Potency - 100/200
CD - 35s to 40s

Final notes:
To make this feel powerful and not overly so, Fleche and Contre Sixte would share a CD, this way either of them could only be used every other melee combo (maximizing efficiency by maxing out the Balance Meter to use a full "Enchanted" combo), and they will provide both power and flair.

I don't expect this to become reality, but I would be A-OK if it happened.