I wouldn't call Heinlein nuts. I think he was deeply interested in the idea of how social mores are a reflection of the times and conditions they exist in. It's one of the things that set him above his peers. The technological advances and space cowboy stuff was just a backdrop to discuss philosophy and morality. He did so in a generally entertaining way. I don't know that he was advocating any particular philosophy or moralism. He was just exploring them. The difference in points of view between Stranger in a strange land, starship troopers, and the moon is a harsh mistress demonstrate that.