Could anyone help me to check whether these sentences sounds natural or difficult to understand?

If it's unnatural or sounds confusing, could you help me to improve it? Thank you very much!!!!

1. First of all, although it’s a lesson to review grammar point, students can learn better if they have an excellent warmer to get students interested in the lesson.

A. You  forgot the s of points as its plural or is it singular? Should it be "a grammar point?"

b. warmup not warmer

C. its not good to repeat words, in this case "students" has been added twice. consider changing the second one to "them"

2.This can be attributed to the fact that the task was well suited to students’ levels, and students are asked to do the task in pairs, which helps weak students gain more confidences

A.the word students is used too often. 

B.Confidence should be singular

3. I suggest that the teacher should try to spend time on post-reading activity next time to give students a chance to use English to communicate.

"Next time" should be at the beginning of the sentence

4. Finally, if she teaches this lesson again, she might like to let her students stay at their seats and speak out loud their answers, or go to the board and write down the part that needs to be adapted.

Should be "in their seats"

"and say the answers"

5. The cases (WC) to use “reducing relative clauses” were also elicited from the students.

Nice sentence but elicited is not a common word it is ok though

6.There is no warm-up activity and the teacher went straight to a matching exercise which requires...

tense issue.... "There is" and "the teacher went".... it should be past or present not both.