The inciting incident, if I'm correct, was his, as well, when he won the ticket to board Titanic. But Jack has no need, doesn't seem to have a weakness, he has no problem, has no ghost and no change of character. And yet he's the one that drives the desire line, and most of the action is taken by him.
Who's the main hero? And who's the first opponent?"
- Roy Saringo
Roy, thanks for the questions. Your analysis is quite correct. You can see why the love story is the hardest genre to structure, since it is the only one with two main characters. Also why a love story with the woman as the more primary of the two characters is even tougher to construct. Plus this story adds the framing device of the old Rose.
Rose does have the weakness, problem, need, ghost and self-revelation. She also has the inciting event, but it is the old Rose who sees the news account of the Titanic excavators. You're also right that Jack appears to drive the 1911 story. But that's because social custom dictates that, as the man, he must take the active courtship role. Plus, she is engaged to someone else and it's 1911.
Jack has no weakness or need, which I believe is a flaw in the script. I think that's because James Cameron wanted Jack to be a rogue-charmer-trickster character, the most popular of all character types. Tricksters typically have a weakness, which is that they lie, steal and cheat to get what they want. But this seldom comes across as a weakness to the audience because the trickster is always fooling unjust authority figures. Of course that is precisely what is happening here, as Jack outsmarts all the stuffy snobs who are oppressing Rose.
In a curious way, Jack is almost a traveling angel character in the story. Rose has a problem in her community and Jack shows up, with no real flaws, and teaches her how to live. He also falls in love with her. This is not unlike the structure of The Music Man. By the way, traveling angel stories are famous for having dual main characters: one character has the weakness, need, etc. while the perfect traveling angel character drives the action.
As for opponents, in love stories the first opponent is the lover. That's certainly true in Titanic, though the conflict between Rose and Jack is not the knock down, drag out variety, and in love stories it seldom is. After all the two are falling in love. The secondary opponents are the family members, like fiancé Cal and Rose's mother, Ruth, along with Cal's security man, Lovejoy. Of course when the story switches from love to action, the main opposition becomes the iceberg, the icy water and the lack of lifeboats.
That brings up one last tip about identifying the genre beats in your story. In today's Hollywood, almost every successful script is a combination of at least two, and sometimes three or four genres. This causes writers all kinds of problems, among them determining which beats to use from each of the different genres that are present. There is no easy answer for this. But first you have to know your genres really well, so you can make informed choices. And second, you have to stay true to your unique story idea. Make the beats work for your story, which means change whatever you have to change. It's not about getting an A in genres. It's about using the genres as powerful tools to tell your story well.