In a large Ziploc bag, add all shrimp marinade ingredients, including shrimp. Seal tightly and gently massage the bag to insure the shrimp is fully coated. Refrigerate in marinade for 30 minutes.
Boil a pot of salted water on the stove. Cook pasta according to directions. Drain and set aside.
While pasta is cooking, begin cooking the shrimp and pasta sauce. In a large pan over medium high heat, heat a drizzle of olive oil. Once hot, remove shrimp from marinade and add to pan. (Discard marinade.) Cook shrimp without moving for 2 minutes to get a slight crust. Flip and repeat on the opposite side until shrimp are fully cooked (about 4-6 minutes total, depending on size of shrimp). Set aside and cover to keep warm.
Carefully wipe pan clean. (It will be hot!)
Melt 2 tablespoons of butter in pan. Add minced garlic and cook 30 seconds until fragrant.
Add tequila and half of lime juice and zest. Whisk together and then bring to a boil. Reduce heat slightly to keep mixture simmering and allow to reduce by half (about 5 minutes.) Carefully taste periodically, and add salt, pepper, and additional lime juice if needed.
Reduce heat to medium. Add heavy cream and remaining butter. Whisk to combine. Heat for 1 minute more. Add pasta to pan and toss to thoroughly combine in sauce. Remove from heat.
Spoon sauced pasta into bowls. Top with shrimp, diced peppadew peppers, parsley or diced scallion greens, and optional remaining lime zest.
Serve immediately.