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.
Peeta would be overjoyed and also very protective. He would constantly be by Katniss's side, making sure she has everything she needs. Gale might have mixed feelings. He still cares for Katniss deeply, and while he would be happy for her, there might also be a tinge of sadness that it's not him in that role with her.
Harry and Ron would probably be shocked at first. Ron, especially, might have a hard time accepting it because of his past relationship with Hermione. But eventually, they would come around because they care about Hermione. Ginny would likely be more open - minded and try to be supportive. Other friends from Hogwarts might also be divided, some might be against it because of the long - standing rivalry between the Gryffindors and Slytherins, while others would see it as a chance for unity in the wizarding world.
It's possible that their family's reaction was initially negative. But as the twins shared their feelings and experiences, the family slowly changed their views. The twins' unity in coming out might have made the family realize that being gay is just a part of who they are, and eventually led to acceptance.