PRINCE JOHANNES VON THURN UND TAXIS, one of Europe's richest men, died Friday at 64 in Munich, Germany. . . . FIVE ISRAELI air force officers were killed when their light plane crashed in southern Israel while on a supply mission. . . . SEVEN VIETNAMESE boat people suffered burns Friday after wrapping themselves in blankets and setting themselves on fire to protest the government's refusal to settle them in the West. . . .