Hi byron!
Thank you for your post.
From Bled, you should go to Plitvice lakes in Croatia. I suggest that you spend a whole day there if you have time. From there you can go to Sarajevo (Plitvice lakes, Bihać, Drvar, Livno, Konjic, Sarajevo).
From Sarajevo to Dubrovnik you could take this route: Sarajevo, Konjic, Mostar, Nevesinje, Bileća, Trebinje, Dubrovnik.
From Dubrovnik to the north i suggest that you visit Hvar island (ferry). For the coastal roads... Well... which ever you choose you will not regret, or you will regret that you do not have more time to ride them all.
Plenty of hotels on the route. On the coast in that period can be tricky to find a room so I would advice to book before you start.
It is a shame that you do not have time for my Serbia, but maybe next time.