In a large bowl, mix the cream cheese, Parmesan, oregano and 1/2 tsp. salt until well combined. Transfer mixture to an 8-inch round dish and spread into an even layer. Spread with the marinara sauce, leaving a 1/2-inch border around the edges. Sprinkle with the bell pepper, pepperoni, basil, mozzarella and olives. Refrigerate for at least 1 hour. Serve with breadsticks, for dipping.