Bring a large pot of water to a boil and salt generously. Add the pasta and cook until al dente. Strain and allow to cool slightly.
In a large bowl, whisk together the olive oil, vinegar, mascarpone, Dijon and 2 teaspoons salt. Add the pasta, shrimp, Parmesan, peas, peppers and fennel; toss to coat. Fold in the basil and dill. Serve at room temperature or cold.