How do the stage directions in Act 2 of The Crucible impact the characters and plot?

The stage directions in Act II help us to understand not only how hard the Proctors are trying to move on with their lives but also how there is still quite a wedge between them.  For example, Elizabeth's attention to John while he eats his dinner shows how much she's trying to please him: she "blush[es] with pleasure" when he compliments the stew.  However, the fact that he had to season it himself before she entered the room shows he did not want to hurt her feelings by implying that it wasn't done to his liking.  As he's eating, "He gets up, goes to her, kisses her.  She receives it.  With a certain disappointment, he returns to the table."  John is clearly trying to make amends with his wife and show her that he loves her, but she seems to hold on to some negative feelings; either she's still angry with him or hurt (or both).  Such directions help us to quickly understand the emotional distance between the Proctors caused by John's affair with Abigail, even before their language shows us.  It does not take long for their mutual anger to bubble over and result in raised voices, Elizabeth "trembling" and John "turning on her."  

If this act were written in novel form, the amount of difference between the two would have a great deal to do with who narrates.  If we have a first-person narrator -- John or Elizabeth -- then the audience would get a lot of information about the thoughts and feelings of that character; we would hear his or her side in those thoughts and thus be more likely to side with them.  However, as it is now, I think we tend to sympathize with and fault them equally.  If we had a third-person limited narrator, the change would be similar.  On the other hand, if we had a third-person omniscient narrator, one who knows the thoughts and feelings of all the characters, I would anticipate an onslaught of information from both characters -- their thoughts and feelings must be wild and scattered and coming quickly -- and so this would lengthen the narrative and slow down the pace of the story, which is not desirable in a scene like this that builds tension for the audience.  

What effects do the stage directions have in The Crucible?

One effect of the stage directions is that the reader has an opportunity to interpret characters' actions that are described but not addressed aloud, and these actions or descriptions of the tone in which certain lines are to be spoken sometimes tell us even more than the words themselves.  They allow us to understand more fully what characters are thinking and feeling in moments when they may not be saying everything aloud or telling the whole truth.  For example, in Act II, the opening stage direction tells us that John Proctor seasons the stew his wife has prepared while she is out of the room.  When she serves him, stage direction tells us that "She sits and watches him taste it."  This helps us to understand that his response to her cooking is important to her, so important that she watches for his reaction when he tries it.  She is anxious.  Further, he tells her that "It's well seasoned."  Now, we, the audience, know that he's not being entirely truthful: he adding seasoning to it, so he must not have found it well-seasoned to begin with; however, he now compliments his wife on the stew when we know that he was "not quite pleased" with it as she'd prepared it.  This is a man who's willing to tell a small lie if he thinks the reason is good; readers know this because of stage direction.

A moment later, Proctor tells his wife that he "means to please [her]," but when he tries to kiss her, she only "receives it" and, "With a certain disappointment, he returns to the table."  With only their words and no stage direction, readers would be much less likely to pick up on the tension in this relationship.  The words themselves are, for the most part, all good, kind, typical of a loving relationship, but the actions betray the sense that not all his well between these two people.