Cook pasta in a large pot of boiling salted water until tender to the bite, 9 to 12 minutes or according to package directions. Drain and rinse thoroughly under cold water until completely cool (see Notes).
Prepare a gas or charcoal grill for medium heat (you can hold your hand 5 in. above cooking grate only 5 to 7 seconds). Thread squash and zucchini chunks onto 10- to 12-in. metal skewers and place on a baking sheet. Brush vegetables with 1/4 to 1/3 cup olive oil on all sides and sprinkle with salt to taste. Transfer to grill and cook 10 to 15 minutes, turning occasionally, or until vegetables are very tender.
Meanwhile, whisk together remaining olive oil, the vinegar, and 1/2 tsp. pepper in a small bowl.
With a fork, push vegetables off skewers back onto baking sheet and toss them in oil left there. In a large bowl, toss together pasta, vegetables, oregano, pine nuts, and olives. Add dressing and salt and pepper to taste; toss. Serve warm or cold.
Note: Nutritional analysis is per 1-cup serving.