1. To prepare pork, combine first 8 ingredients in a small bowl. Rub sugar mixture evenly over pork. Let pork stand at room temperature 1 hour.
2. Preheat oven to 225°.
3. Place pork on the rack of a roasting pan coated with cooking spray. Pour 1 cup water in bottom of roasting pan. Place rack in pan. Bake at 225° for 1 hour.
4. Combine 1/2 cup vinegar and ketchup in a medium bowl; brush pork with ketchup mixture (do not remove from oven). Bake an additional 3 hours, basting every hour with ketchup mixture.
5. Pour remaining 1 cup water in bottom of roasting pan. Cover pork and pan tightly with foil. Bake an additional 3 3/4 hours or until a thermometer registers 190°. Remove from oven; let stand, covered, 45 minutes.
6. To prepare sauce, combine 3/4 cup vinegar and remaining ingredients in a small saucepan. Bring to a boil over medium-high heat, stirring occasionally with a whisk. Boil 5 minutes or until slightly thick. Shred pork with 2 forks. Serve with sauce. Serve shredded pork on hamburger buns with pickle chips, if desired.