PREPARE the DRESSING: Grate 1/2 teaspoon fresh lemon zest; KNEAD and cut lemons into halves to juice, yielding 2 1/2 tablespoons juice; WHISK together remaining ingredients well; SET aside.
BRING bring 6 quarts water to a boil in a large pot; ADD 1 1/2 tablespoons kosher salt and spiral pasta, returning to boiling; COOK pasta according to package directions (do not overcook -- pasta should be al dente).
DRAIN pasta well; RETURN pasta to pot and toss with a very small amount of olive oil to prevent sticking; LET stand to cool.
PREP all pasta salad vegetables and fresh herbs to specifications; PLACE prepped vegetables into a large bowl.
ADD the cooled pasta to vegetables in bowl, combining well.
ADD 4-6 ounces cubed or crumbled feta cheese, without tossing.
WHISK the DRESSING mixture again; POUR the DRESSING evenly over pasta salad; GENTLY fold pasta salad over from the bottom a few times to evenly distribute the dressing and combine feta cheese.
CHILL pasta salad at least 2 hours to overnight.
GARNISH pasta salad with parsley sprig, or fresh basil or mint leaves.