Suburban Retailing for the New Brooklyn
Continuing boom in housing fuels retail revolution in Brooklyn with large stores opening along its East River waterfront; home furnishers and hardware giants fill unmet consumer demand in areas formerly occupied by industry; some longtime residents see megastores as disruptive force to small businesses and small streets, while others welcome amenities and jobs they bring; Loew's hardware store in Gowanus section has encountered little opposition since it serves largely local consumers; planned Ikea store in nearby Red Hook, however, is seen as destination retail experience and faces challenges from middle-class, mostly white, residents who have revived area; photos (L)