[itsme]

I agree with Sciurius that separate settings for more of the displayable items are required. Not only size and visibility but also text colour, highlight colour, bold, italic and so on.
"all" could be discussed, but independent settings for subtitle, comment, comment italic, comment bold are definitely needed.
That's not possible with the current settings window, a redesign would be required.
Btw: I doubt that sliders are the best UI element for the font sizes. I would prefer e.g. an edit box combined with +/- buttons. I think that would be easier to use and take half of the space.