“WILLIAM POWHIDA: The Writing Is on the Wall,” Schroeder-Romero, New York, NY. Through May 16 Holland Cotter: William Powhida, art world vigilante, virtuoso draftsman, compulsive calligrapher, fantasist autobiographer and recently self-announced gallery owner and art dealer, has a semi-solo show at Schroeder-Romero well worth catching. As in the past, Mr. […]