Sure, Tanjiro masters Sun Breathing in the manga. It's a turning point that showcases his determination and progress. It also ties into the broader story and his quest for justice.
Inosuke doesn't become a Hashira in the manga. The story progresses with him having other significant experiences and achievements instead of achieving that specific position.
It's hard to give an exact number. Different story arcs and battles led to the deaths of multiple hashira. Some died heroically, while others met their fate in unexpected ways. The count changes as the manga progresses.
Definitely not. Genya remains outside the ranks of Hashira throughout the manga. This is because of a combination of factors such as his skills, experiences, and the overall direction of the story.
Well, it varies. In some stories, the Daleks' sheer power and ruthlessness give them the edge. But in others, human ingenuity, courage, and unexpected alliances can tip the scales in their favor.