OK, first, you're killin' me Smalls with that spelling. It's "Austen." /rantover

Second, I'll try my best to answer as many of these as I can, but I don't know the answers to them all.

Was it realistic that everyone seemed to know that so-and-so makes "five-thousand a year!" or that marrying a certain girl would get you twenty-thousand?

The short answer is yes. The slightly longer answer lies in primogeniture and how wealthy the families were. A man's income is derived from the size of his estate, or what was left to him by his own father. In Mr. Darcy and Mr. Bingley's cases, they were beneficiaries of large estates, that would generate even more income if proper taken care of. Let's take the Darcys as an example of dowries. Darcy had one sister, Georgiana, who had something like 40,000 EDIT: 30,000 pounds as a dowry. This would have been settled on her by her father as a means to see her happily married. The larger a woman's dowry, or the portion she could bring to a marriage, the better marriage she'd make. In short, she could basically afford to marry for love, rather than marrying for secuity. The Bennet sisters, in comparison, had something settled on them like 5,000 for the rest of their life. They wouldn't ever be expected or able to work, so imagine being given something like $100,000 and being told "Here, this is what you have FOREVER UNTIL YOU DIE. Now, go marry, have kids, buy a home and a car, and try to survive." Would you rather be told that and handed $100,000 or $800,000?

Did these people actually do work? Did they take part in the management of their estates? I fully realize that the books are intended as romance and social commentary, and so they would not focus on the dull details of day-to-day. But looking at Emma, for example . . . neither Emma nor her father seemed like the type to be managing an estate. Did they put all of the effort of running their estate into the hands of other parties, and just reap the benefits?

The successful ones did. As previously mentioned, the books are intended as a skewer of society, and not as a true-to-life retelling, so you shouldn't really expect to see them managing their estate. However, in Emma there is absolutely a scene where Mr. Knightley is speaking to one of the farmers on his estate about the farmer's plans to marry Emma's friend Harriet. he is not only asking Knightley's advice, he is asking (in a sense) for his landlord's permission. In a large estate like that, whoever worked and lived on it would have been expected to run any major life changes past their lord. Knightley is absolutely in charge of his land and you can see that a small example of managing it.

In addition, I don't think The Woodhouses (Emma's family) actually owned a lot of land, but were rather just very deep pocketed from relations gone before. If they were, it certainly wasn't integral to the plot to see Mr. Woodhouse managing his land, so I'd guess that's why we don't. However, you can see in several cases that Emma is a sort of landlady of the estate, and often goes to visit the poor. This would have been a female's way of managing the estate. The men take care of the nitty gritty business stuff, the women take care of the people that live and depend on the wealthier family of the estate. She would have heard their problems and sent medicine, money, food, or whatever else was needed to them.

Also in Emma, there is a family which used to be a family of means, but which were reduced to a well-bred family with no money. They were forced to give up their estate and live in a humble house in the city, with few or no servants. How did that work? What happened to their income?

Honestly, I don't know. I don't think the readers were never given that information about the Bates family. However, we could surmise that it might have been a long time coming (since they obviously don't own any land or have jobs to keep the cash flow) or it might have been sudden, like a bad speculation.

EDIT: /u/oddlikeeveryoneelse provided this great piece of detail further down the thread that I didn't remember. Cut and pasting it here so that more people see it: "The Bates never had an estate. Old Mrs. Bates had been married to a prior vicar who was long dead. So their previous income had been from the living that the Mr Elton now enjoyed and of course being the local vicar they had had the same place in local society that the Eltons now enjoyed. Miss Bates and Mrs. Bates were left to live off of whatever settlement had been made on Old Mrs. Bates at her marriage which was clearly not enough to maintain the style of her married life. If Mr. Bates had lived longer they might have built a savings for Miss Bates to live on, but as Mr. Knightley points out she will only grow poorer before she dies."

In Pride and Prejudice, on a visit around the country-side, a family (which otherwise seemed proper and normal by the day's standards) just drove up to Darcy's estate and demanded a tour of the place. That seems crazy to me. Like "Hey, let's drive up on to Wolf Blitzer's summer home and have the maid show us around!" Any insights here? If this was realistic, why was it customarily allowed?

This is absolutely realistic and is still done today in England. It's actually a way to keep old houses like Chatsworth (where the P&P movie was filmed) or Highclere Castle (where Downton Abbey is filmed) running. They take donations from visitors and a portion of the house is open to public viewing. In Regency England, almost the entire house (except for the private family rooms) would have been fully open to any guests, at any time, so long as the master wasn't in residence. That is one of the reasons why Elizabeth consents to visit Pemberley, because she doesn't think Darcy will be there.

For further reading/watching, I highly recommend the PBS documentaries on Highclere Castle and Chatsworth. As well as Secrets Of The Manor House also on PBS.

Hope that helps!

I can attempt to answer some of your points from an economics/economic history point of view. In Jane Austen's period the top decile of the populace owned 80% of all of the wealth in Britain, and the top 1% owned 50% of all wealth. Wealth in this case means non-financial assets such as land and estates, and financial assets, mainly government bonds. In this period there is no real patrimonial , (capital owning), middle class.

The only way of having a high standard of living was either inheriting an estate, or marrying into one, where one would hope to receive a large dowry. One could not hope to obtain this level of wealth by work alone.

So, these people are the rentier class, not in the modern pejorative sense, but people who could live entirely off the income from their wealth. Given the average income in 1850 was around £50 a year, only a very small number of people could afford to live off the returns from capital. Indeed, the income talked about in Austen's books that is required to have a comfortable life is around £5000 per annum, as you mentioned.

Source: Capital in the 21st Century, Thomas Piketty.

Not exactly to the question you're asking, but I want to point out that Austen was not trying to write "romances". She wrote subtle satire.

In fact she skewers the Romance genre in Northanger Abbey. I'm not sure that one's been filmed, so I encourage you to read it. The protagonist goes to visit a friend's family home and arrives with preconceived expectations of the romance the house must contain. She is brought to ridicule for her ideas.

Also in Emma, there is a family which used to be a family of means, but which were reduced to a well-bred family with no money. They were forced to give up their estate and live in a humble house in the city, with few or no servants. How did that work? What happened to their income?

This is the fate which awaits the Bennett daughters if they don't marry well, and the Dashwoods similarly, in P&P and S&S. We don't know the story behind the fall of the Bates family, but it wasn't uncommon, because land and income generally followed the male line (eg the Bennett entailment), with possibly spare cash (generally held in the form of Government bonds - as mentioned by Mr Collins during his suit for Elizabeth) being settled on females at marriage.

As a follow-on question to this: how important was it for a woman's prospects in Regency England that she had a large dowry versus, say her good looks or other charms? In Pride and Prejudice, Austen makes much of the fact that Jane Bennett is very beautiful, for example, and that Elizabeth Bennett is very clever, but that they are both at a disadvantage at a relatively small dowry (I believe 5,000 pounds, if memory serves). Conversely, in the same novel, Mr. Wickham attempts to elope with Georgianna Darcy, despite her youth and poor health, presumably for her large inheritance potential.

Could a woman be very beautiful and intelligent, and still not desirable? Would a rich man be more likely than a man of more modest means to care about intrinsic characteristics than money?

Other's have already given really good answers, but you might also look into the David M. Shapard edited versions of Austen's novels. They're very heavily annotated (so much so that there's one page of text and on the facing page are the annotations for that page) and provide really wonderful and in depth insight and information into the novels. You can get all of the novels except for Mansfield Park, which I think is due out in September of next year.

I recommend you look at a book on precisely this topic: 'What Jane Austen Ate and Charles Dickens Knew' by Daniel Pool. It has both specific information about money and laws, and good general commentary on social matters.

these are all very interesting replies, but is anyone going to take a stab at the main question: How realistic are these aspects of her books? So far the answers seem to imply "yes." But...?