What an interesting list! I have never associated the dark part of Balkan stories with anything gothic, but they have a lot in common now that i think about it. I would also add: Spring Flowers, Spring Frost and The general of the dead army by Kadare, Time Shelter by Gheorghi Gospodinov, The Old Man and The Wolves by Julia Kristeva, The Fratricides by Nikos Kazantzakis, Mademoiselle Christina and With the Gypsy Girls by Mircea Eliade and The Green Parrot by Martha Bibescu. If you also add books that are not translated in English you can add Paturi oculte by Doina Ruști, Invitatie la vals by Mihail Drumes and Alexandru Lăpuşneanul by Constantin Negruzzi. And if you are interested by books with action in the Balkans but where the authors are from other places, you can add The Tiger's Wife by Téa Obreht.