The difference between democratic socialism and social democracy has gotten very fuzzy in the US and maybe elsewhere. Like Marx and most traditional socialists, I am a fierce believer in democracy. Two illustrations of that tradition:

"the first step in the revolution by the working class, is to raise the proletariat to the position of ruling class, to win the battle for democracy" —Marx and Engels, The Communist Manifesto

"Without general elections, without freedom of the press, freedom of speech, freedom of assembly, without the free battle of opinions, life in every public institution withers away, becomes a caricature of itself, and bureaucracy rises as the only deciding factor." —Rosa Luxemburg

As for Rachel Dolezal, do you think trans people should say the equivalent thing, or are they right to say they are what they believe themselves to be?

I share your fascination with passing. It reveals how arbitrary these things are.