Can you please check the grammar in the following sentences, please?

Question

Thank you very much in advance.

1)If I hadn’t missed it, I would have arrived on time at the theatre and I could have seen Murphy’s performance.
2) I don’t feel well and I’d prefer to go to bed early.
3)Mrs. Ryan would prefer the children to stop playing (or would rather they stopped playing) because they are sweating.
4) She told me that her father was angry with her because she hadn’t passed her biology exam.
5)Sandra wishes her boyfriend hadn’t bought her a golden ring for her birthday.
6) It is high time you tidied up your room.
7) Melanie said she wouldn’t tell anything to her boyfriend because she wanted to make him a surprise.
8) If my friends had had a map, they wouldn’t have got lost. I’m used to getting up early/I was used to sleeping after lunch.
9) She begged them not to do anything dangerous.
10) She suggested I go (or I should go) to bed early.
11) I just wanted to remind you that you will be having lesson in (or with?) the third class on Wednesday.
12) She refused/offered to help us.
She suggested/recommended/proposed/
admitted/denied going to the party

Answer 1

3)Mrs. Ryan would prefer that the children stop playing because they are sweating.

In #7, I'd use "give" rather than "make."

In #10, either phrasing will do.

In #11, the preposition you choose changes the meaning slightly. What is meant by this?

All the others are fine.