Also the whole defending multiple monarchies thing.

Marxists would critically support a monarchy if it was a progressive step under the conditions.

I disagree that Luffy is an anarchist or a revolutionary.

He is absolutely on a journey where he is building up the forces that will fight in revolutionary alliance alongside him through good deeds he's done to make these people his allies. Whether he intended for that to occur or not it is what is happening. He will be thrust into the role of revolutionary.