Sense and Sensibility Theme of Society and Class

The world of Jane Austen's Sense and Sensibility is a complicated one, in which everyone fits neatly into minute little pigeonholes in the incredibly stratified, hierarchical class system. Imagine this system as an enormous card catalog, in which every single person we encounter fits somewhere – and moving them to another place is quite a big undertaking, that involves shuffling everyone else around slightly and getting them all used to it. Her characters are all painfully, obsessively aware of their individual positions in society, and all of their relationships are marked distinctly by their varying amounts of power within the social system.

1. Most of the characters we encounter in Sense and Sensibility fall in the vague category we call the middle class. Can you differentiate between them? If so, how?
2. What kind of impact do society and social convention have upon the various characters in Austen's novel?
3. Is there any single "correct" take on social convention here? If so, what is it?
4. Is social class a limiting factor here, or do characters manage to get around it?

Movement between social classes is possible (though difficult) in Austen's novel; more important than birth or status is the presence of ambition.

Sense and Sensibility largely avoids the question of birthright or nobility, and instead focuses on wealth as a means to social status, implying a shift in the English class system of Austen's time from nobility to economic measures of power.