As to my trip, it was great. Crazy and tiring, but we had a great time. In brief: the Czech Republic - amazing caves, Croatia - the most beautiful, Montenegro - the most friendly people, Sarajevo - very depressing, Hungary - very independent with a reasonable government and the pearl of Budapest. We had to go through the passport (or ID control), but no problems at the borders. We could see some migrants on the way in Hungary, but not many of them.