So you think all soap operas sound the same? This suds column’s for you. To separate the lather from the scum, I’ll periodically size up a show (in this pathetically short space). This week: one life to live on ABC. High marks for: Social relevance. Created by Agnes Nixon in 1968, it was among the first soaps to have major story lines about blacks. Last year it took on homophobia. * But wait: The current story about date rape was complicated by making it a gang rape. And the victim, who can’t remember the crime, also has lupus. Why isn’t one disaster ever enough? * Honor roll of grads: Tommy Lee Jones, Tom Berenger, Laurence Fishburne, Judith Light, Phylicia Rashad, Richard Grieco. * Worst part: The theme, less melodic than nails on a chalkboard. * Hunk/babe factor: Definitely a show for straight guys. * Recommended dosage: Twice a week.