My opinion on Mrs. Bennet is that she does not hold her daughters’ feelings important. She doesn’t want Jane to marry Bingley because their characters are suited or because Jane loves him, but because she wants all her daughters to marry to whoever asks them (before they even meet Bingley she plans for him to marry one of her daughters). Bingley knew how Mrs. Bennet made inappropriate remarks about Jane having caught him and how Jane would be mistress of Netherfield when Bingley didn’t even approach Mr. Bennet. He had to know Mrs. Bennet would continue to encourage the match whatever her daughter’s feelings. if you interpret Mrs. Bennet differently we will have to agree to disagree.
I actually agree with you that most of the characters, events and coincidences in P and P are plot devices, primarily planned to move the plot forward and to get the main characters to where the author needed them. I differ in that I think Darcy is equally important to Elizabeth (although the narrating POV is primarily hers). I think he counterpoints a lot of what is shown in Elizabeth’s character. Just like the aspect that has been quoted a lot in this discussion thread: the debate about firmness of opinion versus being easily persuaded. As others said, Darcy ends up acting using the principle professed by Elizabeth in their debate, while Elizabeth wishes Bingley to be what Darcy stood for: steadfast. It can also be argued that both of them have a different kind of pride and a different kind of prejudice which their interaction exposes and they both try to improve.
You say, if I understand correctly, that because both Bingley and Jane are plot devices, their characters are formed for this purpose, and that Bingley’s abandonment or Jane’s final acceptance can’t be measured against expectations for real actions of real people.
I think Jane Austen’s greatness lies (partly) in the fact that even her „plot device” characters can still be imagined as flesh and blood persons. There could be such girls as Jane, interpreted by some as extraordinarily naive, impossibly angelic, introverted perfectionist, a warmhearted truly kind girl… and such young men as Bingley, whom so many readers wish to „finally grow a spine” but so many others like for being the modest, unselfish, considerate person who wants the happiness of the girl he loves even if it can only be without him. These characters inspired so much discussion and interpretation, so many fanfiction story to discover their character potentials in spite of primarily being „only” plot devices.
