Not exactly. While there are hints of a potential romantic connection between Midoriya and Uraraka, their relationship hasn't explicitly culminated in a full-fledged couple status by the latest manga chapters.
Midoriya would initially be in shock. But then, his heroic instincts would kick in. He might try to analyze Toga's behavior and find a way to use it against her. For instance, if he notices that she gets distracted easily, he could create a diversion. He would also be thinking about the safety of others. He might worry that Toga has some bigger plan that involves harming his classmates or the city. So he would be constantly looking for a way to not only escape but also stop Toga's potential evil plans. And throughout all this, he would be drawing on his training at U.A. to keep his composure and think rationally.
His closest friends like Ochaco Uraraka and Tenya Iida would most likely side with him. They have always been there for Midoriya and share his values of justice and doing what's right. Also, those heroes who have seen Midoriya's growth and believe in his pure intentions would probably join his side.
Other characters' reactions can vary widely. Some of the more empathetic classmates, like Tsuyu, might offer words of comfort and stay by his side. Mineta might be a bit more cowardly, but still show some concern. The teachers, such as Aizawa, would take charge of the situation. Aizawa would ensure Midoriya gets proper medical attention and also start an investigation if the injury was due to foul play. His mother, if she were to find out, would be extremely worried and rush to be by his side as soon as possible.
Definitely not. Midoriya's character is very much alive in the manga. The creators have no intention of killing him off as he's a key figure in driving the narrative forward and inspiring other characters.
Midoriya's character development would be quite distinct. In his new form as a girl, he would have to re - evaluate his self - identity. He's always been a determined boy with a strong sense of justice. But as a girl, he might find that the world expects different things from him. This could lead to a struggle between his old self and the new self he's becoming. He might also develop a more nurturing side, which could enhance his hero capabilities in a different way. For instance, he could be better at calming down panicked civilians during a disaster. He would also have to deal with new forms of discrimination or assumptions based on his new gender.
In fanfics, Midoriya and Asui interact in various ways. They often have conversations where Midoriya's enthusiasm rubs off on Asui. For instance, Midoriya might be excitedly talking about a new hero technique he wants to try, and Asui will listen intently and offer her practical advice.