1. Combine 1 T. barbecue seasoning and 1 tsp. salt; rub evenly over pork roast.
2. Stir together tomatoes, next seven ingredients, remaining 1 T. barbecue seasoning, and remaining 1/2 tsp. salt in a 6.5 quart slow cooker. Add roast; cover and cook on LOW 9 hours, or until meat shreds easily.
3. Remove roast; remove and discard bone. Shred meat using the tines of two forks. Return to slow cooker, and stir together with sauce; spoon over multigrain buns. Serve with pickles, if desired.