In a food processor, combine the yogurt, 2/3 cups peas, and 1/4 cup of olive oil. Pulse until combined and set aside.
Use a mandolin slicer or a regular vegetable peeler to slice the zucchini and summer squash into long thin strips. Work around the squash as you make your way inwards. Stop when the texture starts to change and you start to see seeds.
Warm two tablespoons of olive oil in a large saucepan over medium-low heat. Working in batches, sauté the zucchini and summer squash ribbons until just soft, about 3 to 4 minutes, stirring occasionally.
Meanwhile, warm the remaining two tablespoons of olive oil in a small skillet over medium heat. Add the pine nuts and red pepper flakes. Cook, stirring frequently, until the pine nuts are golden brown, about 4 minutes. Set aside.
Toss the squash pasta and yogurt sauce in a large mixing bowl. Add the remaining peas, basil, Feta, and toasted pine nuts. Add fresh cracked pepper and 1/2 to 1 teaspoon of sea salt, to taste. Gently toss and serve immediately.