1. I think the nurse ghost bug is solved in current update.
2.I got SCM-835 15/20 times when playing Sakurai house. Just wanted to confirm if you can too. The problem you mentioned, does that happen when ghost see you hiding?
4.People are mentioning they still face problem with her quest. I know there was one when you get her message second time and try to interact with the book. But it's been resolved I think. Don't know if it's because players don't know how to do her quest or it's just something I'm not able to find.
During initial stage of Jiyon's quest she doesn't appear from front entrance like Sunaga. She appears from some place else.