Though in the books he is also an insecure asshole to harry and hermione again and again - until he comes around this in Deathly Hallows. Its basically rons character arc to overcome his insecurities.
Hermione is vindictive. Kidnapping and blackmailing another person in book 4, being rude to Luna when she meets her, getting mad at Harry when he gets the Prince's book and gets better than her at potions.
Harry's biggest flaw is his impulsiveness, which leads to the events at the end of book 5.