Preheat oven to 400°F. Heat oil in heavy large ovenproof skillet over medium-high heat. Add shallots, garlic and crushed red pepper and sauté until shallots soften, about 3 minutes. Remove from heat. Let stand 5 minutes. Sprinkle fish with salt and pepper. Add fish to skillet; turn to coat with shallot mixture. Roast fish in oven until just opaque in center, about 10 minutes. Transfer fish to platter; tent loosely with foil to keep warm.
Using oven mitt to hold handle, set skillet over medium-high heat. Add Marsala, clam juice and vinegar and boil until sauce is almost reduced to glaze, about 7 minutes. Season to taste with salt and pepper. Spoon sauce over fish; sprinkle with pine nuts and serve.
