In Goethe's Hand, Pig's Game, and Children's Game wrote a novel in which the protagonist cannot bring himself to send the titular document to his rival working under Arthur Thiele.  
Dramas by this man include one in which Eckermann is the insignificant assistant of the titular poet, one following a street singer who fakes blindness to increase his donations, Jorg Graf, one in which Asti backs down on his threats to kill his father.  This playwright of In Goethe's Hand, Pig's Game, and Children's Game wrote a novel in which the protagonist cannot bring himself to send the titular document to his rival working under Arthur Thiele.  That novel features this author's recurring character Franz Horn.  This author's other novels include one in which Kaltammer demolishes the title structure after it is lost by real estate agent Gottlieb Zurn and one in which Klaus Buch is inadvertently thrown into the sea during a stormy boating trip by Helmut Halm.  FTP, name this German novelist of Letter to Lord Liszt, The Swan Villa, and Runaway Horse.
Dramas by this man include one in which Eckermann is the insignificant assistant of the titular poet, one following a street singer who fakes blindness to increase his donations, Jorg Graf, one in which Asti backs down on his threats to kill his father.  
Martin Walser