I thought, if wp do not find any custom css settings, it will use the css from the parent theme. The partent’s css comes witn an @import into the style.css of the child theme and should have a lower priority (means, the child#s css will overwrite the parent’s css.
No, unfortunately no. Please take a look at the source code. WordPress insert first the style.css file of the child-theme, then the style.css file of the parent theme.