First let me say I think this is wonderful and you have done a good job. I do think that with thread work you will solve some of the issues others have spoken about if they bother you. So much can be added with layering thread. I wonder if some of your concern is that think you need to reproduce the photo as much as possible in as much detail as possible. Nothing wrong with that if that is what you want to do but you can also edit the scene by giving not the details but the overall feeling. I'm not trying to say you should do it one way or another, just trying to give you something to consider. Maybe you already have.
As I said at the beginning, I think you are doing a great job so far. I know layering in the thread will make a huge difference too. Just don't be afraid to put on a lot of thread. Sometimes it takes a lot to really work well.
For what it is worth!