Modern Macedonians are definitely 100% Slavic, both culturally and linguistically. Yes, we are similar to all the South-Slavic nations, especially with Bulgarians.
Genetically doe, no. Roughly 16% of the Slavic gene consists in the Macedonians. Same with the other South Slavs, some have more, some even less..
>The rest are Albanians
Excuse me, but Albanians do not call themselves Macedonians.
And those Greeks you mentioned were Grkomans (Grkomani).