There are so many fanfictions out there, and while the idea of 'Naruto kills Teen Titans' is quite a unique and probably controversial concept in fanfiction, without actively searching through specific fanfiction sites, it's hard to find and describe. Fanfiction often takes creative liberties and can have very different interpretations of characters and their actions.
Power imbalance could also be a reason. If Naruto's power suddenly goes out of control or he misjudges the Teen Titans' power levels and thinks they are a danger to his world or friends, he might take extreme actions. For example, if there's some kind of power - up in Naruto that makes him overly confident or paranoid, he could lash out at the Teen Titans thinking he's protecting something important.
Naruto could fit in by sharing his knowledge of the ninja world. This could include things like how to make different types of ninja tools or how to perform certain stealth techniques. In return, the Teen Titans could teach him about teamwork in a different way than he's used to in Konoha. His unique abilities like summoning animals could also be a huge asset when they are up against tough enemies.
One possible fanfiction could be where Orochimaru somehow gets involved in the Teen Titans' world and meets Red X. Maybe Orochimaru is after some sort of powerful artifact that the Teen Titans are protecting. Red X, being the mysterious anti - hero, might initially see Orochimaru as a potential ally to get his hands on the artifact for his own gain. But as the story progresses, he realizes Orochimaru's true evil nature and teams up with the Teen Titans to stop him.
Well, Naruto could bring his unique ninja skills to the Teen Titans. His Rasengan could be a powerful new attack in their arsenal. Maybe he'd teach them some of his chakra control techniques too.
There are indeed. In some fanfictions, the authors might explore how Naruto's ninja skills and Raven's magic could combine in combat. It could also be about cultural exchange, like Naruto introducing Raven to the shinobi way of life or Raven showing Naruto some of the more mysterious aspects of her world. The possibilities are quite extensive in the realm of fanfiction.
In Naruto x Teen Titans 2016 fanfiction, an interesting plot could involve a quest. Let's say there's a powerful artifact that has the potential to disrupt both Naruto's world and the Teen Titans' world. Naruto and the Titans would have to work together to find it first. Naruto could use his tracking skills, and Raven could use her magic to sense the artifact's location. Cyborg could provide technical support, and Naruto could help with physical combat against any guards or obstacles in their way.
Naruto's powers could complement the Teen Titans' abilities. His superhuman strength, which comes from his chakra, could be on par with some of the Titans' physical powerhouses. And his ability to sense danger using his ninja senses might give the Titans an edge in their missions. For example, if they were facing an enemy that was hiding or about to ambush them, Naruto could sense it and warn the team.
Well, in a Sage Naruto and Teen Titans fanfic, Naruto could bring his unique ninja skills. Maybe he'd teach the Titans some cool jutsu like shadow clones. His sage mode would give him an edge in battles against the Titans' villains. He could also share his experience of growing up an outcast in Konoha, which the Titans might relate to as they often face being different from the norm.