This episode's headline: Restarting START; Mid-School Crisis?; Profile - David Toma; The Face of Change. The guests include RONALD LEHMAN, Director, ARms Control Agency; DEBORAH MEIER, Central Park East Secondary School; GOV. BILL CLINTON, Arkansas; CORRESPONDENTS: DAVID ROSE; JUDY WOODRUFF; JOHN MERROW; ESSAYIST: ANNE TAYLOR FLEMING. Byline: In New York: ROBERT MacNeil; In Washington: JAMES LEHRER