Returning to the fandom since V3

It’s been a very very long time since I’ve engaged in any Danganronpa content so I have questions.

1. What is 2X2?
   Is it just a remake of the second game or something else?

2. Kiri’s burn scars?
   I know there was the Danganronpa Kirigiri novels that went more into her backstory. When I was still in the fandom it was still ongoing, did we ever get an answer to what happened or did they just leave it a mystery?
   (I don’t personally care for spoilers so just let me know, if we still don’t know please fill me in on any fan theories, I love seeing what everyone thinks.)

Also please let me know where I can read the novel please.

3. What happened to the V3 cast?
   So obviously we have the Danganronpa 3 anime that sheds some light on the second game cast, but did we get any information on the V3 cast after the game?