Heat 2 tablespoons olive oil in a large skillet over medium-high heat. Add the zucchini and cook for about 15 minutes. (I do not cook the zucchini with the risotto, as it would get too soft; by sauteing it on a higher flame I'm able to achieve a different texture, and I like it much better when added to the rice.) Remove the zucchini to a plate and reserve. Heat 1 tablespoon olive oil and 1 tablespoon butter in a second large skillet over medium-high heat until the butter is melted and foamy. Add the shallots and saute until tender, about 3 minutes. Add the rice and cook, stirring, to toast it. Stir in 1 cup wine, reduce the heat to a medium-low simmer and let the alcohol evaporate for about 3 minutes. Stir the rice constantly; do not get distracted and let it become dry. As the liquid gets absorbed, begin adding the vegetable broth, one ladle at a time.
Meanwhile, as your risotto is cooking and while you are stirring, heat the remaining 2 tablespoons olive oil and 1 tablespoon butter in a medium skillet. When the butter is melted, add the shrimp and sprinkle with salt and pepper. Add about three-quarters of the parsley and remaining 1/4 cup wine. Cook over medium heat for about 3 minutes, and when the shrimp turn bright pink remove from the heat and set aside. Do not discard the juice.
Once the risotto has cooked for 20 to 25 minutes, and as your vegetable broth is almost finished, start tasting the rice and feel its consistency. If it needs more time on the stove, you can ladle in some warm water to keep it going a few minutes more. Stir in a couple tablespoons of cheese, if using. (Italians do not like to see cheese and fish together, so I use Parmesan almost as a seasoning while I cook the rice.)
If you've done everything right, this is the moment to stir in the already browned zucchini and the cooked shrimp; the sauce from the shrimp will help the risotto gain the final 5 minutes of cooking time without the need of any additional water.
Ladle the risotto into serving bowls. Sprinkle with the remaining parsley and drizzle with olive oil.