Thanks for your suggestions. Unfortunately, I tested them all. For example, I write documentation in LaTeX or Markdown. For adding text or marking something most software you named are great but acrobat is more powerful and can change the PDF on original places with something remarkable like font recognition. Not that I like the Adobe environment, absolutely not, but I have to admit no one beats acrobat. So I used pandoc most of the time to convert PDF to Markdown and back. So long as the PDF has OCR text is great. If not, I decided to make a new PDF instead of changing the old one. This is to much hassle with FOSS software.