American Lit. Read Aloud. First Time

1. I am apprehensive today about using the read aloud method in American Lit. I know that this is the best way for students to improve their writing but I am concerned students will not take it seriously or will allow their fears to sabotage the effectiveness of this assignment. 
2. I am afraid that students will either provide useless feedback to their peers or that they will be mean and malicious. I know it is possible for students to provide positive and constructive feedback but I am not sure how to encourage this.
3. Best case scenario: each student walks away from today with a slew of positive and constructive feedback. I hope that each student feels better about themselves as a writer and also has a clear path forward to improve not just this essay but their future essays as well. I hope that students will grow in confidence as writers and be more willing to share their writing in the future.
4. Worst case scenario: Crash and Burn. Everyone is mean to each other or not constructive. Students may get their feelings hurt and allow assumptions about what other people are thinking about them/their writing to take away from what could be beneficial. Today is a risk, both for me and the students. The worst case scenario might lead to failure. What do I do if everything falls apart?