I have not yet seen any redeeming characteristics. I really want him to be the guilty party, he is so unlikable. But so far, there is no evidence that he has done anything beyond making himself very undesirable.
He says disputes Parrish's claim that he broke off with Juliet Kendall. The father says that he was upset when FP asked for a lock of his daughter's hair. Darcy does not seem convinced that Kendall did the breaking off of the engagement.
Who to believe! As much as I dislike Kendall, the lock of hair story lends credence to his claim since Parrish just made the same request of Elizabeth.