Dan-app, thank you so much for this extensive and very helpful explanation.
I have a few more questions for you:
1) You suggested me to choose English Literature - how much knowledge of English Language do you need for this academic subject? Is it generally hard for those whose native language is not English?
2) What about Biology and Chemistry? (briefly, difficulty)
3) Politics - is this good choice?
I will definitely avoid choosing Art, probably Business Studies too.
I want to choose 4 academic subjects, as you wrote above, and maybe I will made the choice you suggested - but obviously, what level in English you have to be? Intermediate, Advanced or what?
Thank you again