PKS timetables I've took from bieszczadyonline.pl
So I'll try to go from Zagorz to Ustryki Gorne (there iz a bus which should? wait? for a train arrival and goes at 6:00, and according to your information arrives to UG at about 8:00), then I'll spent some time there (maybe I'll try to go on Tarnica), and return to UD by bus from UG at 13:25.

Thanks.