Yes, Naruto can heal himself without Kurama.
This ability of his only strengthened over time and by the end of Naruto, he could easily heal from most injuries without much trouble. Without Kurama, Naruto can no longer risk taking heavy damage in battle as he won't recover like before.
Although Naruto usually uses the Six Paths' Sage Mode along with the Kurama Chakra Mode, there is no reason he cannot use it without Kurama's strength. In fact, Naruto can still use the basic Sage Mode, which is enough for him to take down a roster of enemies.
Naruto, without Kurama, would not be able to keep up with Kaguya's immense chakra reserves and diverse abilities. The battle against her was hard enough with Kurama, but it would be almost impossible for him to win without Kurama's power.
Although the Boruto anime has only just shown the Baryon Mode, fans know what it means for Naruto and Kurama. Baryon Mode is a strength only accessible to Kurama and his Jinchuriki, where the chakra of both fuse together, similar to nuclear fusion, and give rise to new energy.
Although Naruto lost Kurama, he still has access to the powers of the other Tailed Beasts. During the Fourth Great Ninja War, he received a portion of the chakra of every Tailed Beast and has utilized this power to a great degree in all his fights since.
Because Tailed Beasts are life-forms made of pure chakra, they are eventually reborn after dying. They will always come back, but until that happens, they're factually dead. So, deliberately creating some new Tailed-beasts to get Kurama back does not seem like something Naruto would do.
At best, Sasuke might be slightly stronger than Naruto without Kurama. However, in the worst case scenario, he might be substantially weaker than the Seventh Hokage. A fair comparison can only be made once both these characters display their true strength after the loss of Kurama and Rinnegan in the Boruto series.
So, the fact remains that although his battle power is hampered without Kurama he still stands to be one of the strongest Shinobi alongside Sasuke. In a battle with him, he can still use Rasenshuriken, Sage of Six Paths Rasenshuriken, numerous Shadow Clones and his Sage Mode powers to put up a good fight.
Despite the loss of his dear friend, the Seventh Hokage can still use the Sage Mode. Fans were delighted to see that Naruto still retained some of his powers and that he is capable of taking down strong opponents. However, he had to use Shadow Clones in order to collect the natural energy.
Now that Kurama is dead, will he come back? No, he ain't comming back. His chakra (his existence as he is made of it) was consumed and literally faded away which he himself stated.
Monsters like Kurama can die, but they do not pass from physical wounds or age. Instead, they die when they expend more chakra than they can recharge, and they have tons of it. This has happened to Tailed Beasts in the past, but they do not stay dead forever.
No. Even if we take into account Sakura fans complaints that she isn't a demigod, doesn't have a Tailed Beast or EMS, i still put Naruto and Sasuke far above her even without their outside power sources. Sage Mode Naruto and MS Sasuke beat Byakugou Sakura with low difficulty.
Naruto did take the advantage of Kurama's power as jinchuriki. However, he also developed several independent skills. He was an Uzumaki and reincarnate of Ashura and hence his chakra's were very deep as compared to most shinobi. His body was also more resilient and stronger.
THIS is when Naruto mixed Six Paths Sage Mode with his Nine-Tails cloak. Some people get it confused. To answer your question, Naruto still has Six Paths Sage Mode after the death of Kurama, but he can no longer generate Truth-Seeking Orbs as he did in Naruto Shippuden.
Naruto lost his Sage of Six Paths (SOSP) power after his fight with Sasuke. It was mainly due to the fact that he lost the chakras of all the bijuus (tailed beasts) that he had. So, as a result of losing the power of SOSP, he also lost the ability to heal.
The Next Power Of Naruto Uzumaki
While most fans consider Naruto to be past his prime, he can still train and grow stronger. Even without Kurama, Naruto can attain great mastery of all forms of jutsu and get even stronger.
1 Baryon Mode
Baryon Mode powered Naruto Uzumaki up to great levels, and made him strong enough to overpower Isshiki Otsutsuki in battle. This transformation made him the strongest character in the story, and is Naruto's strongest form by far.
The movies that followed Naruto Shippuden made it even more ambiguous, however, thanks to Boruto, fans now know that Naruto Uzumaki does indeed have the Six Paths Sage Mode, as seen when he used multiple Tailed Beasts' Chakra against Delta, and even managed to fly in several of his fights.
4 Won't Surpass: Naruto Has Kurama
Boruto does not have a powerful tailed beast inside of him. This is a source of power unique to the jinchuriki and Boruto is not one. Without Boruto having that power, Naruto can remain stronger than his son.
Sakura Haruno is a skilled shinobi who boasts considerable physical strength. But she really shines in the field of medicine as she was trained by the greatest medical ninja of all time, Tsunade. However, if the Boruto two characters went up against each other, Kakashi would win despite losing his Sharingan.
It turns out the Tailed Beasts never actually die, but they reincarnate over the years. The first instance of a Tailed Beast dying happened with Isobu. The monster was killed alongside his host, and it forced the beast to reform over the years.
The Nine-Tailed Fox died in the battle against Isshiki, with Naruto returning to the Hidden Leaf de-powered. His superhuman chakra no longer exists, due to Kurama, which leads to Konoha's science team tending to him. Sarada is taking charge, as she doesn't know the lasting effect for her longtime colleague.
According to a theory elaborated by fans, Sasuke never actually lost his Rinnegan, he just needs a catalyst to re-awaken it.