All great points. You confirm what I instinctively feel - my questions have too much information, but I should find ways of being more succinct, not deleting vital parts of my question. I feel like I have isolated the problem as much as I can in my most recent question, but in other questions, maybe I'm being a bit too general. Thanks!

I've updated the images to have highlighted areas.

I disagree. I think we want to give more prominence to the editing section, because that's where we're actually doing something. When I'm typing, I'm not looking at Preview. It's great for seeing how Markdown formats something, but I use it like to check what I've written, not to watch whilst I'm typing.

I think it's a usability issue which is why I brought it up. Of course I resized the window, but that doesn't change the fact that several times now I've tried to edit the preview. I don't think it's a critical issue, or even an important one, but it is an issue nonetheless. If it can be fixed easily, it just makes StackOverflow a bit easier to use. How is this a bad thing?