I believe Drama comes from Greek Hydrama.
What about the cities in Thrace? Do you have a slavic name for Xanthi, Komotini and Alexandroupoli?? I think they might of had a Turkish name, one was Dedeagach, but no sure which one, im not an expert on Thrace
If im not mistaken , Constantinople = Tsarigrad in Bulgarian ??
Another interesting fact is how some of the older Western Bulgarians call the Aegean sea 'BeloMore' after the 40's this newer name came 'Egejsko More'.
The Belo More is called so by Bulgarians because of the calm water as opposed to the rough waters of the Chorne More .