Hard to say. Geoff Johns' plans can change, and it depends on various factors like creative inspiration and publisher decisions. We'll have to wait and see.
I'm not sure specifically about the Kowalski family's story at Johns Hopkins. It could be about their medical experiences there, perhaps a family member's treatment, or it could be related to their academic involvement at the institution.
I wouldn't recommend looking for free ways to watch it as it might be illegal and could get you in trouble. You should use legal streaming platforms that have the rights to show the movie.
Definitely not. Manhwa comes from Korea. It has unique features that set it apart from Chinese comic works in terms of art style, storylines, and cultural influences.