No they do not interact because superior feint does not require a bluff roll. With superior feint you miss with your one of your attacks and the creature you were supposedly attacking is denied its DEX bonus until the beginning of your next turn. This means the target loses its DEX bonus vs all other attacks by the swashbuckler in this turn. It would also lose its DEX bonus vs any AoO the target provoked in the next turn before the swashbuckler acts.
Confounding shield allows you to take 10 on your bluff roll when using a normal feint. Since superior feint does not require a bluff roll the ability to take 10 is irrelevant.