Hello. Although this question refers to the play "The crucuble" you did not inform the point of the play to which you ask these questions, which makes it difficult to answer accurately.
Elizbeth is portrayed as a sick character, which we can see that physically she is very weak and does not have the liveliness that other characters, like Abigail does. This can contribute to the lack of attractiveness between John and her, in addition to contributing to his initiative in looking for a lover. Elizabeth is also portrayed as a cold and emotionless wife at the beginning of the story, but shows a strong loyalty, courage and affection for John throughout the narrative.
Building a fire is an act of technical skill and technology, and fire in literature has also often been used as a symbol of knowledge. The building of a fire thus symbolizes life in the story, but also life through human knowledge, skill, and technology.
Each paragraph you write should have a main idea or dialog basically those things see when you write if you have more than one main idea it confuses the reader.