Before Guy jumped out of the balloon, he was asking Lili how she thought a man is judged after he is gone. She responded with A man is judged by his deeds, the boy never goes to bed hungry. Guy took this as an approval to go forth with his search for freedom. Guy is not judged after death based on the act of killing himself, he is judged based on his deeds and actions while he was alive.
I was definitely caught off guard when he jumped out of the balloon. Why didnt he take his family with him!? When Lili and Guy were lying in the grass together he said Sometimes I just want to take that big balloon and ride it up in the air. Id like to sail off somewhere and keep floating until I got to a really nice place with a nice plot of land where I could be something new. Id build my own house, keep my own garden. Just be something new. I was left wondering what his little family would do to survive now. He was the main provider and Lili was always building him up and trying to make him feel like a man. I was also confused as to why Guy would want to put his son on the list to work at the mill if thats not what Guy even wanted to do in his life. I would have thought he would feel the same way as his wife in that he would want a better life for their son instead of just working at the only mill in the area.