Inosuke survives throughout the manga. The story doesn't have his death as part of the plot. His character remains active and plays a significant role until the end.
In the manga, Tanjiro and Kanao don't end up getting married. The story focuses more on their battles and character development rather than romantic pairings.
I would recommend 'Douma's Secret Admirer'. In this fanfiction, the reader is a shy character who secretly admires Douma from afar. It's full of cute and endearing moments as the reader tries to get closer to Douma without being too obvious. It's a really heart - warming read.