Two years have gone by since General Motors stopped building cars at its massive assembly plant in Ohio. While some of the 1,600 workers decided to retire or start a new career, most went to GM’s plants around the country as far away as Texas, Tennessee, and Missouri. But today, many of those autoworkers are finding that their futures are just as unsettled. Worries about the fast-changing auto industry and the stability of their jobs have left hundreds unsure whether to uproot entirely. Many are still splitting time between where they work and where their families still live in Ohio.