Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
I'm not a fan of online literature. I'm just a person who likes to read novels. I don't have the ability to know the update date or other relevant information about the Spiritual Domain animation. If you need any other information about the Soul Domain animation, please let me know. I will try my best to answer your questions.
In the manga, Sukuna doesn't possess all 20 fingers. There are specific story arcs and events where his finger count changes based on the plot developments.
In the manga, Sukuna does acquire all his fingers over the course of the story. This is a significant plot development that has major implications for the storyline and character dynamics.