As of the latest chapters I've read, Megumi is still alive in the manga. Usually, such major character deaths are significant plot points and would be well-publicized if they occurred.
Sure. In grade school, I saw a paraeducator work with a special needs student who had autism. She created a visual schedule for the child to follow the daily routine. In high school, for a special needs student with a cognitive impairment, the paraeducator modified the curriculum to make it more accessible, like using simpler language in history lessons.
Typically, megumi fanfic often focuses on his personality traits. His stoicism and determination are often highlighted. For example, in many fanfics, his unwavering resolve in the face of danger is a central theme.
Well, Megumi's story in the manga was full of twists and turns. She had to overcome various obstacles, and there were also some unexpected developments in her relationships with other characters.
Nope, Megumi is alive. The author has chosen to keep Megumi's character alive to continue developing their story and interactions within the manga's world.