Are the human beings Leon Trout describes a million years in the future truly human?

Why does Leon Trout choose to remain on Earth instead of going into the blue tunnel, and why is he prepared to leave at the end of the book?

Trout's experience spans a million years, but he chooses to tell a story concentrated around 1986. Why is the story of the first castaways the center of Trout's tale?

What role do luck and chance play in the story?

Why does Vonnegut jump around in time and space as he tells the story?

What drives Mary Hepburn to artificially inseminate the Kanka-bono women?

Compare the society of 1986 to the society of a million years in the future. Is the future "Eden" better than human civilization?