(Photo credit: Caleb Wertenbaker) David Schweizer, acclaimed stage director, died of a heart attack on Dec. 4 in New York. Schweizer’s career in opera included directing the world premieres of “The Greater Good” by Stephen Hartke and Philip Littell at the Glimmerglass Festival, “The Long Walk” by Jeremy Howard Beck and Stephanie Fleischmann at Opera Saratoga, “Elizabeth Cree” by Kevin {…}