Jem wants to make sure that Atticus can't hear his disrespect. Jem wants to preserve his perfect relationship with his father.
Due to the fact that the restaurant is very good , it attracts a lot of people
Well, in his letter to the church he states that the problem needs to be reveled and fixed. For the people like him who are not being shown equality "it is like sinking in quicksand". He mention multiple reason for equality. The main purpose of that letter is so the church would make a change.
hopes this helps
Editing and Proofreading I believe. Hope this helps :)))))))