Dzien dobry. Really depends on where you plan to go, if you stay in ¨east (middle for some) EUR then probably normal tickets/advance are best buy.

The MIN for a pass-easy to see on the site, is for 4 days in 1 month, including 2 days in home-country (for you only on PKP-IC on PR and KD-NOT the other locals!). IF you can manage to reach final destination on an overnight, you might be able to reach it with 1 travelday, but 2 would probably be more realistic But again-without more details impossible to say.

Zloty-conscious Polski most often turn to WIZZair in the end

I would go to Istanbul from Krakow. 

Istanbul - Poland would need atleast 3 Traveldays but currently no Railservice from Turkey to Bulgaria/Romania 

Istanbul - Bucharest (no trai service from Turkey toBulgaria& Romania) 

Bucharest -Vienna or Budapest 

Vienna/Budapest -Poland

Oh yes. I think I’d go by bus to istanbul from Sofia maybe

Istanbul - Sofia will run again from 25.4. Sofia - Istanbul starts on 26.4. From 3.6. from/to Bucharest (only in summer):

https://www.economic.bg/bg/a/view/noshten-vlak-otnovo-shte-pytuva-po-marshrut-sofija-istanbul

Oh Thanks