The Last OG is purely fictional. It was made up by the writers to offer viewers an engaging and imaginative story rather than being rooted in real events.
Tanjiro might use his sense of smell to detect hidden threats. Since his sense of smell is super - enhanced, he could sniff out any demons or traps in the way of saving Rengoku. For example, if there are demons disguised as allies, Tanjiro would be able to tell by their scent.
Well, without knowing the exact nature of the 'order of throne og glass novels', in many series, the order helps in understanding the character development. As the story progresses through the novels in order, we see how the characters grow, change, and interact with their changing environment. This could be similar for these novels too.
It's not a true story. 'The Last OG' is a creation of the writers' imagination. Tracy Morgan's role is fictional within the framework of the show's made-up plot.
Yes, in some fanfictions, Tanjiro is depicted as the reincarnation of Yoriichi. This concept adds an interesting layer to the story as Yoriichi was an extremely powerful and legendary figure in the original lore. The idea allows for new storylines where Tanjiro might inherit some of Yoriichi's skills or have a deeper connection to the past events related to Yoriichi.
Tanjiro's fate in the manga is that he ultimately passed away. This event was a significant part of the story's development and had a profound impact on the other characters and the overall plot.