> SOFT AS NAILS: It was nihilism as usual on stage at a recent Nine Inch Nails concert in Columbus, Ohio, until tragedy struck Trent Reznor's best friend, Maise, a golden retriever. Handlers were walking the pooch on the arena's third-floor balcony when the dog jumped onto a railing, then plunged 50 feet to his death. Reznor heard the news after the set and revealed a sensitive side. ''That was really tough for him,'' says a spokeswoman. Reznor promptly canceled a concert two days later. Says the spokeswoman: ''He flew straight to Miami. He thought (the warmer weather) might cheer him up.''