I certainly dislike Mrs Bennet more than even Caroline Bingley, and her behavior was horrible. However, by the laws and customs of the time, she was entirely dependent on her husband, and it's easy to see how being in that position would make her a little crazed. But I agree that it's a bit of a toss-up as to who was the worst.

As to Bingley, yes, getting rid of his sister is imperative. But apparently he could be talked into things by almost anyone (recall the conversation at Netherfield about leaving in 5 minutes), and who'd want to be married to such a person? And think how much worse this would be when the wife has no independence. I think that would be even worse than being married to someone who was dependable but never listened to you, and I couldn't stand that, either.