Bernard Pomerance, who died last year at age 76, is best known for having written that brutal little lesson in humanity, The Elephant Man. That play’s best line, “We have polished him like a mirror, and shout hallelujah when he reflects us to the inch,” nicely encapsulates the playwright’s concerns over the societal tendency to perform acts of charity for the sake of the giver. But, as is discovered in the wandering world premiere of Spin Off, which was drafted in 2003 and revised in 2006, Pomerance’s thought processes were not always so tidy.