Rate my hypothetical Balkan trip itinerary. I'd be taking trains and busses, with a scenic ferry from Split to Dubrovnik.
Only one transport leg longer than 5 hours.

I'll probably do this within the next 5 years, unless I get a gf and she wants to go somewhere less autistic like Spain

Slovenia:
2 nights Ljubljana
2 night Bled
Croatia:
1 night Zagreb
2 nights Split
2 nights Dubrovnik
Bosnia:
1 night Mostar
2 nights Sarajevo
Montenegro:
2 nights Kotor
Serbia:
3 nights Belgrade