Place the shrimp in a nonreactive bowl. Mix the olive oil, lemon juice, garlic and red pepper in a measuring cup or bowl. Season lightly with salt and generously with black pepper. Pour half the mixture over the shrimp. Sprinkle half the parsley over the shrimp and gently, but thoroughly mix together with a wooden spoon. Set aside to marinate for about 30 minutes.
Start the coals for the grill. You want medium-high heat.
Yes, meanwhile, start the pasta. Bring a pot of water to boil and cook the orzo about 1 minute less than being al dente. Reserve some of the cooking water, just in case, and drain the pasta. Set aside.
When your coals are just about ready—and just before grilling the shrimp—finish the pasta. Heat a sauté pan over medium flame. Add the remaining marinade to the pan and cook until you smell the garlic, about 45 seconds. Stir in the wine and cook for a minute or 2 to reduce slightly. Stir in the cooked orzo, using a spoon to break it up if it's stuck together. Stir in the lemon zest. Heat through, about a minute or two. Turn off the heat and cover.
Now (not meanwhile), grill the shrimp. Oil the grate (or better yet, use a perforated grilling grate—can't recommend this enough for avoiding shrimp falling through the grate). Arrange the shrimp in a single layer and grill for about 3 minutes. Turn and grill on the other side until just cooked through and opaque, 2 to 3 minutes. Transfer to a plate.
Assemble everything. Gently reheat the orzo, if needed, then remove from heat, stir in the remaining parsley and season with salt and black pepper. If the pasta seems dry (mine didn't), add a little pasta water to it. Divide between 2 shallow pasta bowls. Top with shrimp and serve.