Billy says that he first came unstuck in time in 1944, long before his trip to Tralfamadore. The Tralfamadorians didn't have anything to do with his coming unstuck. They were simply able to give him insights into what was really going on. (2.11.1)
So the novel clearly distinguishes between the cure for Billy's existential angst—the Tralfamadorians—and whatever caused him to become unstuck from time. Billy's time-travel appears to be a symptom of his overall suffering. The moment he truly begins to realize he is in deadly danger behind enemy lines, he flashes forward beyond death, back before birth, and then to the moment when he almost drowned trying to learn to swim.
Chapter 2, Section 19
Billy, after all, had contemplated torture and hideous wounds at the beginning and the end of nearly every day of his childhood. Billy had an extremely gruesome crucifix hanging on the wall of his little bedroom in Ilium. A military surgeon would have admired the clinical fidelity of the artist's rendition of all Christ's wounds—the spear wound, the thorn wounds, the holes that were made by the iron spikes. Billy's Christ died horribly. He was pitiful. (2.19.15)
One reason Billy does not seem to seek comfort in God (even though he is a chaplain's assistant before he is taken captive by the Germans) is that he associates Christianity with a suffering Christ. Billy himself is frequently compared to Christ—in the epigraph and because of his job in the army—so why would he seek solace in a religion that is okay with his suffering?
Chapter 2, Section 33
Weary drew back his right boot, aimed a kick at the spine, at the tube which had so many of Billy's important wires in it. Weary was going to break that tube.
But then Weary saw that he had an audience. Five German soldiers and a police dog on a leash were looking down into the bed of the creek. The soldiers' blue eyes were filled with a bleary civilian curiosity as to why one American would try to murder another one so far from home, and why the victim should laugh. (2.33.6-7)
Billy isn't really laughing, though it looks that way; he's actually convulsing. Why does Weary decide to add to Billy's suffering by bullying him on the battlefield when they are both in danger? What does this say about Weary's character?
Chapter 3, Section 15
[Billy] was under doctor's orders to take a nap every day. The doctor hoped that this would relieve a complaint that Billy had: Every so often, for no apparent reason, Billy Pilgrim would find himself weeping. Nobody had ever caught Billy doing it. Only the doctor knew. It was an extremely quiet thing Billy did, and not very moist. (3.15.1)
The reason for Billy's weeping may not be apparent to the doctor, but is it apparent to us? Beyond Billy's war experiences, what else might he have to cry about?
Chapter 4, Section 9
And now there was an acrimonious madrigal, with parts sung in all quarters of the car. Nearly everybody, seemingly, had an atrocity story of something Billy Pilgrim had done to him in his sleep. Everybody told Billy Pilgrim to keep the hell away. (4.9.16)
An "acrimonious madrigal" in this context is a loud, furious, multipart harmony of people yelling at Billy. No one in the POW train car wants to sleep next to Billy because he whimpers and kicks so badly in his sleep. Why does no one ever show any sympathy for Billy's suffering? How do you respond to Billy's extreme portrayal as helpless and childlike? How might this portrayal fit into other themes such as fate and free will or men and masculinity?
Chapter 5, Section 53
Billy looked inside the latrine. The wailing was coming from in there. The place was crammed with Americans who had taken their pants down. The welcome feast had made them as sick as volcanoes. The buckets were full or had been kicked over.
An American near Billy wailed that he had excreted everything but his brains. Moments later he said, "There they go, there they go." He meant his brains. (5.53-6-7)
War stories often contain descriptions of wounds, but this book has little time for wartime casualties. We do, however, get a lot of illness: Weary's gangrene, Wild Bob's fever, and the soldiers' diarrhea here, to name a few. This focus on the suffering of the sick human body really underlines the physical exhaustion and deprivation these POWs must cope with throughout the novel. Also, by focusing on diarrhea instead of, say, a bullet wound, Vonnegut is once again drawing the reader's mind away from any kind of battlefield heroism.
Chapter 7, Section 11
So Billy made a [syrup] lollipop for [Edgar Derby]. He opened the window. He stuck the lollipop into poor old Derby's gaping mouth. A moment passed, and then Derby burst into tears. (7.11.2)
Edgar Derby, who has been the strongest of the American POWs throughout the whole book, is reduced to tears by the taste of syrup in his mouth after so much hunger. Again, this novel really takes the romance out of warfare and exposes the incredible deprivation that war really brings to the men fighting it.
Chapter 8, Section 26
Nobody talked much as the expedition crossed the moon. There was nothing appropriate to say. One thing was clear: Absolutely everybody in the city was supposed to be dead, regardless of what they were, and that anybody that moved in it represented a flaw in the design. There were to be no moon men at all. (8.26.2)
From a distance, from the perspective of the American fighter planes flying over Dresden, no one can be allowed to live. The pilot doesn't know whether he is shooting German soldiers, civilians, or even Americans. This kind of detached perspective on killing is what makes massacres like Dresden possible. Even someone as cold and callous as Bertram Copeland Rumfoord recognizes that it must have been especially hard for Billy to experience Dresden's firestorm at ground level.
Chapter 10, Section 10
The Maori Billy had worked with died of the dry heaves, after having been ordered to go down in that stink and work. He tore himself to pieces, throwing up and throwing up. (10.10.3)
Even without being injured directly, the presence of so much death is so incompatible with life that it kills this Maori soldier from the inside out.