Dear friends, 
I've let at least one of you down, and I want to apologize. I'm hoping this blog post will reach you, and any other readers who might feel the same way. It takes guts to tell me how you feel, and I don't want you to think your concerns are unnoticed. So, whoever you are, thank you for bringing this up in your amazon review. You said: 

One of the things I love about your writing is that it doesn't create an artificially perfect heroine or hero with a few flaws, but rather you create a whole character with many complex facets who might not make the choices that you or I would - you even stated as much in your blog post. I realized this is one of the reasons why you write such good characters because you allow them their freedom to be who they are the good and bad. So I understand your reasoning for having Kasper Stark and Joseph make the immoral choice they did - their backgrounds alone made it understandable. However, I find myself disappointed because of that part in the book. I was hoping that when all odds and maybe other characters were making wrong choices that the main characters I grew to love would change and/or make the moral choice. I was rooting for the change in Joseph and the better choice from Kasper. 

First, may I say that I'm thrilled and flattered that you care about Klara and Josef enough to be bothered by their choices? If they are real enough to root for, I feel like I'm succeeding as a writer. 
Now, about moral choices. We all make them. We all have a standard of things we will and won't do. If I was writing a story about myself, I would write a book about a girl who's a committed Christian, who makes mistakes, but who tries to make the world around her better because it is the right thing to do, and her duty to a loving God. This girl has an unfortunate habit of profanity, and she isn't always as patient as she should be to her family or herself. This girl married young, because both she and her husband wanted to honor God by not having sex outside marriage. 
There could be a story about this girl, but if I've attempted to write it at all, it lives in the shadows of Laura and Jasper in Courting Scandal, and very attenuated shadows they are! 
This girl is not Klara Stark. 
When I began imagining The Dark Before Dawn, the setting was always Babylon. Not everyone will see the Congress of Vienna that way, but that is how it appears to me--glittering, gaudy, rotten with self-interest and deceit. None of the people that live in this place that I dream of measure the world like I do. Their experiences are different. And thank goodness! I never want to blackmail someone in a crypt and get stabbed. 
I am not as emotionally vulnerable as Klara or as bitter as Josef. I think, like you, they are capable of being better than what they are. But they are living in Babylon, and I don't think they even know it yet. 
Will they? Well, I don't want to drop any spoilers. This is a three book series, so whatever happens will take some time. Their world is full of choices, some I'd make and some I wouldn't. Not everyone believes in Babylon or wants to leave it behind. Elijah is fascinating to me, but so is Jezebel. I'd love to hear her side of the story. 
That said, you expect things from me. I'm glad you do, because it means I did other things you liked. If you haven't fallen under the spell of this story like I have, please wait. This series has, and may continue to disappoint you, but Babylon isn't the only place I dream about. I have another book in the works, Scalpel's Edge, with a heroine whose yardstick looks more like my own. 
For me, there are days to read Fifth Business and days to read A Man For All Seasons, but some will prefer one or the other.  And if all the religious imagery underpinning my stories is a surprise, (as I'm sure to some readers it is) I will confess here that I can't help it. I've been steeped it in all my life, and whatever you believe, the King James Bible is beautiful writing. I think it's where I fell in love with words. 
As ever, wishing you lots of happy reading,