I have changed to indent of my text and the footnote. But the black line above the footnote-text is still too far on the left. How can I move it to the right like the rest?
AFAIK you can’t set a custom indentation value for the footnote separator; you can only set its alignment (left, center, right - using the page style properties). So, if you want to “indent” the footnote separator, you’ll have to modify the left page margin. This has the advantage that you don’t need to define custom indentation for the different page elements (main text, footnote separator, footnote text). If there are any reasons not to modify the left page margin, please add them to your question.