I would be fine with killing him off if they did well but as you explained later on in your post, They didt handle it well which is not shocking considering how sasuke and naruto have been nerfed just to make burito look better
Canon is subjective nonsense made up by the community to exclude...
To make money and to get fanboys excited
Kawaki is the current rival character what do you mean?
What defines as awesome is subjective.
Zabuza is by far the best villain in naruto as his goal and ideology are clear yet never contradicted like even his care for haku was hinted at...