If Sanji did hit a woman, he would choose to die. It sounds extreme, and it is extreme, but it is SO important to everyone in this story to stay true to yourself. Resolve is everything. Willpower -- conviction -- Haki -- is literally your source of power. A character's resolve and sense of self is just as important as their dream. Luffy has his dream, to be the Pirate King, but he also has the resolve to say it to a Yonko. He's always had that resolve. He'll say it to Shanks, he'll say it to Zoro, he'll say it to Garp, he'll say it to Kaido -- it doesn't matter to him. He doesn't care what the obstacle is. He will not give up Zoro has his dream, to become the strongest swordsman, and it's backed up by his own resolve. He swore to never lose again and he means it -- not only would he rather die than surrender, but he would rather die than lose a fight. That resolve is everything. That force of will is what will make or break his dream. Sanji has his dream, to find the all blue and be a great chef. But that doesn't define him as much as Luffy or Zoro's goals. What DOES define him is his resolve to be the model person; to keep his humanity; to never hit a woman. If his resolve was weak, he would be weak. Haki IS willpower. Sanji will remain true to himself, or he will die. That is his resolve. (or he will lose his resolve and become unfit to travel with the straw hat pirates.
When i see people saying that sanji doesnt have will power it bothers me alot. When we see his "fights" against black maria and kalifa it confirms what you said, that sanji would rather die than betray his convictions and this is why i think that sanji will unlock conqueror haki at least by the end of the serie.... He is one of the character with the strongest willpower......
