Angel, I really enjoyed reading your article. I guess C1 in DALF is similar to C2 in CEFR. I found CPE reading and writing easy only because I have a maser's degree in journalism. I actually don't think it's very fair to those whose life doesn't involve a lot of reading and writing.

I also want to comment on fluency. I really like Cambridge's definition of fluency - ability to communicate without much hesitation. It doesn't say anything about the quality of communication. I talked to many people who spoke really fluently but I just failed to understand them - wrong grammar, poor vocabulary, lack of cohesion. Because they weren't my students I couldn't correct them or help express their ideas in a clearer way. So it resulted in miscommunication. So when students tell me that their aim is fluency and they envy those who speak english 'fluently' I usually explain that fluency doesn't mean quality and it's better to speak more slowly but in a way that will make people understand you.

Привет, Уго!

1) Мне нравится + Nominative Case = мне нравится русская культура и литература

2) русский is an adjective = русский язык

3) по-русски is an adverb = говорить по-русски, писать по-русски

4) правильный is an adjective = правильный выбор (the right choice)

5) правильно is an adverb = всё правильно, правильно (correct, right)