1. Preheat grill to 350° to 400° (medium-high) heat. Whisk together first 3 ingredients, 2 Tbsp. olive oil, and 1 tsp. rosemary; reserve 1/4 cup. Pour remaining mixture into a large shallow dish or zip-top plastic freezer bag; add pork, turning to coat. Cover or seal, and let stand 10 minutes.
2. Meanwhile, cook barbecue sauce and reserved 1/4 cup mixture in a medium saucepan over medium heat, stirring occasionally, 3 minutes or until bubbly. Remove from heat.
3. Remove pork from marinade, discarding marinade. Thread pork onto skewers, leaving a 1/8-inch space between pieces. Sprinkle pork with salt and pepper.
4. Thread peaches and bell peppers alternately onto other skewers, leaving a 1/8-inch space between pieces. Drizzle with remaining 2 Tbsp. olive oil, and sprinkle with remaining 1 tsp. rosemary.
5. Grill pork and fruit-and-vegetable kabobs at the same time, covered with grill lid. Grill pork, turning occasionally, 7 to 8 minutes on each side or until done, brushing pork with barbecue sauce mixture during last 5 minutes of grilling. Grill fruit-and-vegetable kabobs 4 minutes on each side or until bell peppers are crisp-tender.