In a medium bowl, toss shrimp with 2 tbsp olive oil, minced garlic, lemon zest, red pepper flakes, and salt. Let sit at room temperature for 10 minutes.
Heat a grill or grill pan to medium-high heat. Brush zucchini ribbons and lemon wedges lightly with olive oil.
Bring a large pot of salted water to a boil. Cook linguine according to package directions until al dente. Reserve 1 cup pasta water, then drain.
Grill shrimp for 2-3 minutes per side until pink and opaque and they reach an internal temperature of 145°F (63°C). Grill zucchini ribbons for 1-2 minutes per side until lightly charred, and lemon wedges for 1 minute until grill marks appear. Roughly chop zucchini into bite-sized pieces.
In a large serving bowl, whisk together lemon juice and 1/4 cup olive oil. Add hot drained pasta, grilled zucchini, shrimp, and torn basil. Toss vigorously, adding splashes of reserved pasta water as needed to create a light, glossy sauce.
Fold in Parmesan and pine nuts (if using). Taste and adjust salt/pepper. Transfer to bowls, garnish with extra basil and grilled lemon wedges for squeezing.