OTTSVILLE, Pa. -- Teresa Heinz Kerry once hinted at tensions with her first-born son, a 37-year-old blacksmith who seeks an anonymous life with his wife and child in rural Pennsylvania..........Heinz Kerry's eldest son lives with his physician wife, Kristann, on a wooded 163-acre farm near Philadelphia, refusing all inquiries about Kerry's campaign, the Heinz foundation, or his own work and ambitions. He operates a small Buddhist high school for troubled teens nearby, and makes reproduction ironwork in a studio on his secluded property, land he has conserved so it can never be developed. On a much larger scale, his mother...