[Senna]

It seems, while Slicing Benten ignores Sweet Smelling's effect. When you use it and strike your target with the whip, it still lowers the charm duration.

[Neus]

This is because it's a dance skill and does not apply the weapon to the damage instance. Undesirable in this instance, perhaps, but not a bug, as that's how all of the dance skills work.

Changing it would mean that dance skills would use weapon accuracy, among other things.

[Rendar]

Doesn't Slicing Benten already use your weapon?

Since It uses SWA. From said weapon.