Alternate Character Interpretation: Although it is indisputable that Fanny loves all three girls and chose good professions for all of them (even taking their ages into account), Sophie notes that the most advantageous profession would be Martha's, Fanny's biological daughter. As a witch, she would not only be very well-off, but she would also meet numerous rich and powerful people. Was that pure coincidence or did she really want the best for her biological child?
Did the Witch of the Waste become like that because she was twisted to begin with and let the fire demon's power corrupt her, or was the gradual destruction of her humanity a natural consequence of using the fire demon's power for decades?
Angst? What Angst?: Sophie is extremely blasé about being turned old, it's not until someone reminds her that her life expectancy has been severely shortened that she starts to think it would be good to lift the curse. Though it's hinted that her initial lack of reaction is due to shock.
Same for when she finds out she's a witch and has been using magic throughout the book. Again, she's rather blasé and accepting. It's not until she thinks about all the random spells she cast that she starts to worry.
Rewatch Bonus: A lot of past scenes are put in a different light once you find out in the last chapters Calcifer saw Sophie's curse and her magic power immediately, told Howl about it, and they were both hoping she could break Calcifer's contract; that Howl's flirtations with Lettie and Miss Angorian were both put-on for strategy; and that Howl is conducting a complicated, deceptive plan over not only the Witch of the Waste and Miss Angorian - who both have their own conflicting gambits - but over Sophie, the entire kingdom, and himself. Almost the only action of Sophie's he didn't predict was her being decent to Miss Angorian.
Broken Base: The fans of the original book, in regards to the movie. Some enjoy the movie as well as the book, while others are not a fan of its admittedly extreme liberties with the source material. Some fans have found a compromise between the two, combining elements of the original book (such as the John Donne poem that serves as a focal point in the book) with the movie's designs in their fan-works.
Counts as this for Miyazaki/Ghibli fans in general. About half think of it as a brilliant piece of art just like every other movie Miyazaki made, while the other half sees it as a convoluted, messy, dramatically cryptic failure. Critical opinion is less divided (apart from Roger Ebert's disappointment with it), and Howl has a solid 87% "Fresh" approval at Rotten Tomatoes. Miyazaki himself considers it his favorite of his films.
Ending Fatigue: The city is bombed, Suliman's henchmen make their final assault! What will the protagonists do? Howl leaves to battle, Sophie takes everyone with her to a safe place and destroys the castle. The Witch of the Wast grabs Howl's heart from inside Calcifer, Sophie pours water over them, breaking Califer's power! She and Heen fall down a chasm. She enters a door into Howl's past, sees him giving away his heart, returns to the present and saves Howl. And saves the turnip, who turns out to be a cursed prince. It's not that it doesn't work, but it does drag on and on.
Hollywood Homely: Young Sophie. She seems to pretty much be the only one who considers herself homely. It's more of a self-esteem problem. It seems she turns old and ugly when she thinks of herself as ugly.
Minor Injury Overreaction: Howl's temper tantrum after having his hair accidentally dyed. Pretty much what one would expect from a super powered child.
Ugly Cute: The Witch of the Waste post-depowering. Despite how hideously obese and aged she looks, her sweet, somewhat oblivious demeanor is endearing.
Heen the Dog. He's short, scruffy, wheezes constantly, and has what look like bird legs, but he's still a loyal, lovable old doggie.
The Woobie: Sophie, particularly when she's first cursed and constantly tells herself not to overreact, when it's clear she's overwhelmed. Then she leaves home because she doesn't want to be a burden. Then her mother sells her out without Sophie even knowing. Life is rough for Sophie.