I have also seen people tell me we're  not slavs.

This is because Bulgars were not originally Slavic tribe, though they are Slavs by culture and language, meaning Bulgars formed ruling class, but were assimilated into Slavic underclass culturally and linguistically. Opposite happened in Hungary, in which Slavic underclass was assimilated culturally and linguistically into Hunnish ruling class. This is why I consider Hungarians to be of Slavic stock, like Bulgarians.

Romanians I am not sure of, but geographically, I assume it must be similar story, since Romanians look like surrounding Slavs.

There are probably non bulgarians on some pics, but its impossible to avoid them, because minorities (turks, gypsies armenians jews) more than 20% of our population

I hardly noticed any. Handful of girls I noticed have features that I would typically guess are Turkish or Armenian, but this is no surprise if 20% of Bulgaria's population is non-native. Still, vast majority of people on this photos do not differ from other South Slavs (OK, Slovenes and Croats seem to have more blondes, and Bulgarians have more Mediterannean examples among them, but otherwise no major difference).