To prepare paella, combine water, saffron, and broth in a large saucepan. Bring to a simmer (do not boil). Keep warm over low heat. Peel and devein shrimp, scrub mussels and clams, and clean all other seafood and set aside.
Heat 1 tablespoon oil in a large paella pan or large skillet over medium-low heat. Add onion and bell pepper; sautè 15 minutes, stirring occasionally. Add tomatoes, paprika, and 3 garlic cloves; cook 5 minutes. Add rice; cook 1 minute, stirring constantly. Stir in lemon juice, two more garlic cloves and chopped parsley, and broth mixture. Bring to a low boil; cook 10 minutes, stirring frequently.
Add seafood to the pan nestling everything into rice mixture.Arrange shrimp, heads down, in rice mixture. Cook until seafood is cooked and shells open; discard any unopened shells. Sprinkle with 1/4 cup lemon juice. Remove from heat; cover with a towel, and let stand 10 minutes. Serve with lemon wedges, and olive oil.