I have almost all fonts set to use "Arial", but i can't find a way to change the font at the top of each lister, in the title bar, to get some consistent look.
Titlebars are drawn by Windows. You used to be able to change the font, although I am not sure there is still a UI for doing so in Windows 10. Changing it would affect all programs (except some that custom-draw their titlebars, of course; e.g. Chrome.)
Hmm, ok. I have "clear type" turned off in Windows, so i was able to get rid of that "washed out" look, because of the font smoothening, in almost all places. Not a big problem, i can live with that.