Yes, he did. It happened in a particular scene where circumstances led to Butch taking that action. The plot twist added a lot of tension to the story.
Yes, he does. In the non - linear storyline of 'Pulp Fiction', Butch's actions play a crucial role. His killing of Vincent is a key event that ties different parts of the story together. It also shows the violent and often unexpected nature of the world depicted in the movie. There are a lot of factors that lead up to this moment, like Butch's own story arc and his interactions with other characters in the film.
It varies depending on the specific scene. Sometimes it's just casual banter, other times it could be something more significant related to their situation.
Butch killed Vincent because of a series of events that led to a personal vendetta. Vincent had previously been involved in situations that put Butch in danger and threatened his life.