Home is indeed a motif in the play. For Biff and Happy, home is a place that they return to as adults but are still virtually in childhood. Psychologists would likely say they are in a state of "arrested development." Home for the boys means they never truly grow up.
Home to Willy is an ideal more than a place. For most of his life he travelled, coming home only occasionally while the boys grew up. He tried to do everything he could to provide a home in the material sense, but emotionally he was absent. Home, to Willy, was always on the horizon.
Home to Linda means keeping the family and her husband together. She tries to have the home in order for Willy and be a safe place for her boys but like her husband, the ideal of her home and the reality of her home are two different things.