I think this is the most respectable Hiro has ever been. He wasn't just gushing over Chiyo or being a pure goofball, he acted (relatively) mature and even tried conquering his phobia for the sake of his daughter.
Speaking of, Chiyo and Wantarou are definitely cute together. "A girl and her dog" is a classic setup, and for someone like Chiyo a pup can certainly be a great way to relax. As for Wantarou biting Hiro, give him some training and that shouldn't be an issue much longer.