What I don't like is the blue highlight colour when you mouse over or click on the menu bar. I think it would look better as a light grey instead.
Can’t you change that as well? I think it is, or should be, affected by the ‘highlight color’ under Settings > General.
I don’t really like the dark mode either, it doesn’t quite fit with most wallpapers I’ve tested. My problem is that you can’t turn it off for either the menu bar or the Dock. It’s the Apple-typical one switch for everything. In addition, the third-party menu bar icons on the right look very strange. They are dark with thick white shadows instead of white. Apple has the technology to change image colours (they added white shadows after all), why can’t they just make them bright? Now you have to wait until third-party developers make updates (if they even think about the dark mode to begin with).