Jin causes everything for the purpose of bringing out Azazel. He knows he can defeat Azazel because of the Devil Gene. He also knows that, if he fights Azazel, it'll probably kill him as well. He's basically trying to kill himself in an attempt to END the Mishima Bloodline. That's basically what comes from Scenario Mode.
Also, there's a chance that he DOESN'T die or gets Reanimated ala Kazuya.
And it seems like Leo and Miguel have the same storyline, where they have someone they love (Mother and Sister respectively) killed by the actions one of the main 'villains' (Kazuya and Jin, respectively).
Again, what pisses me off is some of the demotions as it were. Lee loses his role as principal rival to Kazuya because of Lars. He loses his role as stereotypical gay character to Leo. Without their rivalry, Yoshi and Bryan seem to wander about aimlessly. Steve could be a wild card in the Anna/Nina feud, seeing as how he's Nina's son. Instead, he's a comedy character now with Paul and Law.
Asuka, whose presence demoted Xiayou, is now demoted to a rivalry with Lili, despite her last name being KAZAMA and being related to Jin. Feng seems to be just there. Hwaorang seems more motivated to NOT be Devil Jin, based on his ending, than to actually defeat his rival since Tekken 3.
The only loops that seem to make sense are the potential Raven/Dragunov storyline and the Armor King II/Marduk and King storyline. Wang I think is finally gonna die.