How does the setting of the village scene impact the plot of the novel and the actions of the main protagonists?

There are actually a few village scenes in the story. The rural setting of these village scenes is central to the plot of the novel and the actions of its protagonist, Okonkwo.
The village scenes demonstrate the extent to which nature and its gods affect the lives of the Igbo. For example, "suspicious" deaths are feared by the Igbo because they believe that such deaths will bring curses from the earth goddess. In the book, Unoka (Okonkwo's father) is said to have died from a swelling in the stomach and limbs. This type of death is considered an abomination to the earth goddess. So, Unoka is taken to the Evil Forest to die alone.
Later, Okonkwo desecrates the sacred Week of Peace and offends the earth goddess. He beats his wife, Ojiugo, for failing to cook the afternoon meal in time. Ezeani, the priest, angrily scolds Okonkwo for bringing the curses of Ani, the earth goddess, down on his people. Without the deity's blessings, the crops will not grow, and the people will suffer. To atone for his sins, Okonkwo sacrifices a she-goat and a hen. He also brings a length of cloth and a hundred cowries to the shrine of Ani. So, we can see that the rural setting is central to the plot: it holds the sacred mysteries that the Igbo live by.
A central village scene can be found in Chapter Five. In this chapter, we learn how the villagers celebrate the Feast of the New Yam. Most importantly, we also learn Okonkwo's perspective about such feasts. Basically, he has little patience with them. Certainly, the feast honors the earth goddess, Ani, who is said to be the source of all fertility. Ani is also the ultimate judge of "morality and conduct" and an intercessor for the living before the ancestors.
The village scene in Chapter Five describes the preparations for the feast. Everywhere, there is a festive spirit, and everyone works to prepare the beloved delicacies. Drums can be heard beating in the background. The people's happiness is tied to the land and its attendant gods. For his part, Okonkwo prefers to rely on his own powers to attain material benefits. The difference in perspective between Okonkwo and his fellow Igbo neighbors is made clear in this chapter.
Okonkwo's detachment from the traditional Igbo gods eventually leads to a deep depression, and Okonkwo later dies in an ill-fated suicide. Always impatient for warfare and bloodshed, Okonkwo cannot resign himself to the changes the white man has wrought in his culture. At the same time, he has little faith in the traditional earth worship his people trust in.
Because Okonkwo has always despised failure, he is fully invested in fighting. His greatest fear is to show weakness of any sort. For him, physical strength must subsume all other "types" of strength; indeed, there must never be a superstitious reliance on an earth goddess for one's happiness in life. This is why Okonkwo advocates war against the white man. He can see no other way forward other than to fight. When his fellow Igbo neighbors refuse, Okonkwo commits suicide.
So, the village scenes are central to the plot of the story and the actions of its protagonist, Okonkwo.