The reincarnation story is not as realistic as the title suggests, but for a green writer, it isn't bad. I love the new Dojutsu, but I find it completely unnecessary when he already has Mokuton. The baby should have been traveling with Tsunade and Shizune after the death of his parents. Backstory I made up: some Senju parents (Tsunade's cousin is the father) leave the village to live safely away from the shinobi life and death. The mother gets assassinated during her pregnancy after the sudden death of her husband. In this story, the being saves the child by having Tsunade walk by and reincarnates you instead of the baby that should not have existed. The mother still dies because this is her fate one way or another. I mean, this is important for the creation of a relevant main character. I believe that the writer would have had an easier time with the story if he added only the Dojutsu to the mc. No need for a headache to sort the backstory, if you know what I mean.
