Cook pasta according to package directions; drain. Rinse with cold water; drain again. Chill until needed.
Place four peach halves, cut sides down, on grill rack.
Grill, covered, over medium-high 8 minutes or until grill marks appear; cool.
Cut remaining four peach halves into ½-inch pieces.
For dressing, remove 1 tsp. zest and squeeze ½ cup juice from lemons.
In a large bowl whisk together lemon zest and juice, mustard, and garlic.
Remove half of the dressing; set aside.
Add pasta, chopped peaches, arugula, and blueberries to bowl; toss to coat.
Season with salt and pepper.
Top servings with grilled peach halves and drizzle with maple syrup. Pass the reserved dressing.