he gambled that he would have a boy to inherit the estate.
First, it is a little unfair to put that entirely on him. If he was progressive, Ms Bennett would have had some say, and quite possibly suggested they try again for a boy. Also they had four girls, which is unlikely, though, about just over 6%.
Second, if they weren't wealthy, it is quite possible after expenses to have too little to effectively save for four dowries (by the time they would need that many). This is debatable, and how much exactbly would a respectable dowry entail. Then it's an issue of favoritism, which daughter then deserves a dowry, or the best, if not all can be treated equally well. AFAIK there have never been good and easy answers for such questions except get richer, or abandon children.
He also did not prepare his daughters for the rigors of the marriage market. The girls were left largely to their own devices, lacking discipline for schooling or development of talent. The younger girls are largely ignorant because of this neglect.
Fair argument, they weren't sent to finishing schools. At least two possible objections leaps to mind. One, essentially the same answer as above, they couldn't afford it. Two, they were not about to let someone else educate their girls. For this latter issue, historically it was unusual for girls to be educated at all, and if they were it was almost exclusively at home (an expert historian may interject here). Also what education that was available, usually tutorship, was often brutal and strictly doctrinaire. William Godwin perhaps exemplifies the most progressive contemporary views on education of the the time. To quote another, he stressed three things
Whether miss Austen had read him, and if so, what she thought is beyond me at present. She might have agreed with him, and thus the attitudes of Mr Bennett could reflect that. Mr Bennett allowing his girls to pursue their interests, and educate themselves, is quite progressive for the standards of her time. Even fifty years later, unless a family had means, it was quite common for young boys and girls to cease education for work at a young age, e.g. the factory children in David Copperfield. I suspect you outrage is a little anachronistic and your expectations possible a little unreasonable for the era.
Mr. Bennett uttered a lot of funny quips, but ultimately they were at the expense of his wife and daughters. The older girls were acutely aware of the impropriety of this behavior. He also fails to rein in the wild behavior of the younger girls, preferring to watch the spectacle with amusement.
He's the only man in a hen house. Do you think he could stay sane without a sense of humor? Also would you prefer him to be a rigid authoritarian? Switch his daughters for the slightest of infractions? That
The older girls were acutely aware of the impropriety of this behavior
suggests their gentle method of education and remonstrance wasn't entirely ineffective.
He also fails to rein in the wild behavior of the younger girls, preferring to watch the spectacle with amusement.
Showing a possibly quite remarkable amount of latitude and by the youngest, lassitude on his part. 'Reigning in' his girls, controlling them, e.g. that they should be seen and not heard, was likely conservative and old fashioned tyranny even then. Mary Wollstonecraft was married to Godwin, again a contemporary. Again though parenting styles are a matter of perennial debate. Even if his quips were tinged with a hint of misogyny, it seems the least of your objections.
As a final note, Mr. Bennett could have prevented Lydia's disgrace. Elizabeth counseled him to control his youngest daughter, and instead he sent her off into an army camp with a virtual stranger as chaperone.
I will argue hindsight here. First, why should he try and control his wild youngest daughter and listen to his sensible oldest daughter (without children of her own), who may have become so, precisely by leaving her be and letting her learn on her own. Also at that point it seems (if I recall correctly), her chaperone mr Wickham had, up to then, only demonstrated good character, and Lizzie and her mother requests his permission, and socializing would excite, interest and improve them, and possibly provide desirable matches (a few notable social climbers, like Nelson, were military).
You make some interesting arguments, but I am happy to conclude (on miss austens part) that they aren't any egregious omissions with regards to Mr Bennett. Basically, a male contemporary might have read it and possibly concluded Mr Bennett didn't act a terrible father, if he wasn't quite a good one. If one were inclined to defend Mr Bennett as a father, some honorable defense of his behaviour could be attempted, even if mine presently is superficial.
If I should reread it again, or watch and adaptation, I will make a note of trying to keep your arguments in mind. Most people maybe focus on the girls and their romantic prospects, will focusing on Mr Bennett might be enlightening on Miss Austens views on fathering and fathers.