Position a rack in the top third of the oven and heat to 400°F.
Put the chickpeas on a small rimmed baking sheet, pat dry with paper towels, then toss with the 1 Tbs. of the oil, 1/2 tsp. salt, and 1/4 tsp. black pepper. Roast until golden and mostly crisp, shaking the pan halfway through roasting, 30 to 35 minutes. Set aside.
Bring a large pot of well-salted water to a boil. Blanch the snap peas until bright green and crisp-tender, 1-1/2 to 2 minutes. Using a slotted spoon, remove the peas from the cooking water to a colander, and run under cold water until cool. Reserve the pot of cooking water.
Cut the snap peas on the diagonal into 1/2-inch pieces and transfer to a large bowl. Add the peppers, tomatoes, and cheese. In a small bowl, whisk the vinegar, garlic, thyme, sugar, pepper flakes, 1 tsp. salt, and a few grinds of black pepper. Slowly drizzle in the remaining 1/2 cup of oil, whisking to emulsify. Stir in the lemon peel, and then pour the marinade over the vegetables. Marinate at room temperature for about 40 minutes, tossing occasionally, or cover and refrigerate for about 1 hour.
Return the pot of cooking water to a boil. Cook the pasta according to package directions until al dente. Drain and return to the pot. Discard the lemon peel from the vegetables. Using a slotted spoon, transfer the vegetables to the pasta, reserving the marinade. Toss the pasta, and season to taste with salt and black pepper. Add reserved marinade to taste.