Add word and character spacing (justification) options to character styles
Allow the justification options within character styles.
Quite often I have different typefaces in one paragraph, which need individual values for the justification of word and/or character spacing. But I can only do the justification for a whole paragraph with exactly one font, ignoring all the other contained typefaces. This leads to word spaces, which are way too narrow or too wide in parts of a paragraph (see the top image). If I could adjust justification options in character styles as I can do in paragraph styles, the problem would be solved!
Tobias's suggestion is very sound, and important. Otherwise there is no way to automate control of the space between words when there are multiple character styles within the same paragraph. Any professional typographer needs this level of control.