answering question 1
i think avoiding errors or mistakes of the students or learners helps the lesson to flow without interruption , in my opinion if you correct the student's error in front of the whole class , it will affect him/her in a negative way where he / she will start to participate less and less not because they don't know but because of having this small fear of making a mistake and to avoid embarrassment.
answering question 2
mostly i tried to do like teacher D in exercise 5, where i spend the last 10 to 12 minutes reviewing the lesson and correcting some of the learners mistakes and focusing on the important points where i noticed my students can be confused about.