The Hashiras would likely show concern. Some, like Shinobu, would immediately start looking into possible medical solutions. Giyuu might be more reserved in his worry but would still keep a close eye on Tanjiro. The other demon slayers would also be affected. They look up to Tanjiro, so his sickness would lower the morale of the group. They would try to support each other while waiting for Tanjiro to recover.
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.
One main sad moment was when Ash was separated from Pikachu. They are such a close pair, and being apart was really tough on them. It made Pikachu feel lonely and Ash felt like he was missing a part of himself.
Time is something that catches people off guard. The past has passed, the future has come, and only the present remains.
Those people who I thought would be together forever gradually disappeared from each other's lives. No farewell, no goodbye, only wishing you happiness.
When a special person appears in your life, you will, you will, you will start to live a different life. This is the meaning of love.
Leaving doesn't mean it's over, nor does it mean you can't start over.