Harry Macklowe wanted to go higher. “Another story up?” he offered with a smile. Mr. Macklowe, a developer with a habit of injudiciously reaching for heights, was pointing to a small steel ladder at the job site of his latest and most ambitious project: a luxurious building at 432 Park Avenue, which, upon completion, will be, at 1,398 feet, the tallest residential tower in the Western Hemisphere.