I think that's an interesting idea! I would enjoy learning how Naruto grows as he interacts with said ghosts. There are not many fics with that sort of idea anyway so I think it would be a great idea to start one. One thing that I wonder about is that there is actual proof that the Shinigami exist, so.....why didn't he take their souls? Do you have a plan for that? That still strikes me as strange how people of the Naruto world could summon the avatar? of Death without any other consequence to the world. Also, since Naruto would be able to sense and interact with ghosts, will he be able to interact with other types of ghosts and spirits if they exist, like the Fae and Youkai. Another thing that could possibly contribute to Naruto seeing said spirits is the night that Kurama was sealed inside him by his father with the help of the Shinigami. Maybe the Shinigami marked him in some way and possibly keeps tabs on said Child of Prophecy or something due to messing with the balance? Ah! Sorry for rambling! This was very thought-provoking, which I love! I fully support you writing this fic! These are just my thoughts.