I have a response for the question about being in meditation while dying. I don’t know a great deal about it but it has come up in the book I am reading a couple of times. The book I am reading is called “awakening the Buddha within” by Lama Surya Das. He mentions that when one of his teachers was about to die the teacher sat unmoving for several days before eventually slumping over and passing on. Apparently some practicing Buddhist prepare for this final meditation over the course of their lives. I don’t know much more than this but at least it is a start.