1. She has just graduated from business college with a marginal education.
2. Ballroom [dancing] is a type of formal dancing.
3. Coloured gentlemen are dark-skinned (African, Indian, etc.) men. A head is a nautical term for a toilet. This obviously refers to the days of segregation where white people did not share their facilities with non-whites.
4. Sorry, I've never heard of this.
5. People have lived their entire adult lives (courtship to the grave) in less time.