Naruto might also gain better chakra control. Hashirama was known for his vast chakra reserves and precise control. Under his training, Naruto could refine his own chakra control, which would make his existing jutsu more efficient and powerful. For example, his Rasengan could become more stable and have greater impact.
Another potential ability is an improved connection with nature. Hashirama had a deep bond with nature. Naruto could learn to sense the natural energy around him more acutely and use it in a more refined way. This could lead to new forms of Sage Mode or enhanced versions of his existing nature - related jutsu.
He could potentially gain an enhanced understanding of wood - style techniques. Since Hashirama was a master of it, Naruto might learn how to create more complex and powerful wood constructs, like huge forests for both offense and defense.
Naruto could gain the ability to manipulate light and darkness, which are often associated with Keyblades. This would be a huge change from his normal chakra - based abilities. He could also use the Keyblade to fly, giving him an advantage in both mobility and combat. Another new ability might be the power to heal, as some Keyblades have restorative properties.
If Naruto became an Ino fan due to Kyuubi's influence, he might gain some mental fortitude. Ino is good at mind - related jutsu, and Naruto could learn from her how to better protect his mind from enemy attacks. Maybe he'd start to develop a form of mental shielding similar to Ino's techniques.
He could gain better stealth skills. Hidan is quite good at sneaking around and Naruto might pick up on that. So he could move more quietly and be better at surprise attacks.
He might gain some of Madara's Sharingan - related abilities. Maybe he could use some of the advanced genjutsu techniques that Madara was proficient in. Since Madara had strong chakra, Naruto could also potentially have an increase in his own chakra levels or a new way to manipulate chakra, like Madara's ability to control the Susanoo.
He might gain Minato's teleportation jutsu. It was one of Minato's signature moves, and with Minato sealed in him, Naruto could potentially access and learn this powerful technique.
He might gain the ability to control wood - style jutsu more effectively. Since Hashirama was known for his powerful wood - style, Naruto could use it to create huge forests for defense or to trap enemies. For instance, he could grow trees instantly to block incoming attacks.
He might gain better chakra control. Kakashi could teach Naruto how to precisely manage his chakra, allowing him to perform jutsus more efficiently and for longer periods. For example, Naruto could use his Shadow Clone Jutsu without exhausting his chakra so quickly.
Naruto could gain the ability to use different forms of his Nine - Tails chakra more effectively. Since Killer Bee has great knowledge about Jinchuriki powers, he could teach Naruto how to access and use his chakra in ways he hadn't thought of before. Also, Naruto might learn new physical combat techniques from Bee, like improved hand - to - hand combat skills or new ways to use his kunai and shuriken.
He could potentially gain some form of Sharingan - like ability. Since the Sharingan is a signature Uchiha power, it makes sense that if Naruto were acting like an Uchiha, he'd develop something similar. Maybe a version of it that combines with his own Uzumaki chakra, creating a unique and powerful new ability. He might also gain better control over fire - based jutsu, as the Uchihas are often associated with fire. And perhaps enhanced perception skills, which are also characteristics of the Sharingan.
Naruto might gain the power of shikai and bankai. Shikai is the first release of a zanpakuto's power, and bankai is the ultimate form. Naruto, with his determination and strong will, would strive to master these forms. Shikai could give him new attacks and defenses, while bankai could make him an extremely powerful force. For example, his bankai could combine his ninjutsu skills with the zanpakuto's power in a unique and devastating way.