Heat a large skillet over medium-high heat, and add the Italian sausage, sliced pepperoni and crushed red pepper flakes. Cook and stir until the sausage is well browned and cooked through, about 8 minutes. Drain fat from skillet. Stir in the spaghetti sauce and salsa. Cook until meat and sauce are hot, about 5 minutes.
Spread the tortilla chips on a very large platter. Spoon the hot meat sauce evenly over the chips and top with the feta cheese, chopped onions, jalapenos, black olives, and sour cream.