Pride & Prejudice : What's the importance of propriety in the novel?? Please HELP?

Their lives revolved around manners and formality:

Jane really liked Mr. Bingley but wasn't able to visibly show her affection because it wouldn't be proper.

The whole family was stricken when Lydia ran off with Mr. Wickham because it wasn't proper. They thought that she had ruined the reputation of their family forever and that none of the other girls would be able to make good marriages as a result.

Caroline Bingley spent every moment she could talking about the improprieties of others. This somehow made her feel like she was better than them.

Mr. Collins spends most of the novel dithering about how he plans in advance ways to offer Lady Catherine De Bourg delicate compliments so as not to offend her.

It seems that most of the novel is about finding ways to behave properly and avoiding offending others at all costs.

Poking fun at propriety is the whole point of the novel. Austen lived in an era where P was Everything. It had importance far and above individual values, feelings, desires, dreams and hopes. Its 'rules' penetrated even into the kitchen, where the cooks had to wear proper clothing.

Austen thought it ridiculous. Mr. Bennet gives voice to this throughout the book. The fact that Lizzy laughs with him over this is a significant clue to her personality.

If you have the read the book, recall moments where characters were being too polite or proper despite their feelings. Like, were there times that certain characters were feeling one way but behaved another way because it would have been socially acceptable? Make a list of them. You might see that many of the characters (esp. Mr. Darcy) chose to conform to social customs rather than follow his heart. I believe he makes a speech at one point to Elizabeth that he proposed to her despite her class standing below him which angers her. It seems that propiety keeps them apart most of the novel, which is a good and bad thing.