Olsen and Johnson--often unfairly remembered as a sort of poor-man's Abbott and Costello, but really much better than that-- star in what has to be one of the funniest/strangest variety shows ever done for network television. Sponsored by Buick and its dealers--who couldn't possibly have known what they were getting for their money--FIREBALL FUN-FOR-ALL is basically Olsen and Johnson's vaudeville routines brought to television, live and with full audience participation, like HELLZAPOPPIN' for the home audience. Broadcast from a theater at 6 Columbus Circle in New York during one of the worst heat waves in the city's history, the heat wave is a constant theme of the show and the comedy, which comes at us from all directions--police and