Cook pasta according to package instructions; drain and keep warm.
In a large skillet, on medium-high heat, melt butter with olive oil; add garlic and sauté until fragrant, ~1 minute.
Add wine, salt, crushed red pepper and black pepper; bring to bubbly boil; lower heat and simmer, uncovered, until wine is reduced by half.
Return to medium-high heat, add scallops and sear each side, ~3 minutes per side; remove from skillet and keep warm.
Alfredo sauce: melt butter in same skillet on medium heat; stir in half & half and bring to a bubbly boil; reduce heat to low and simmer ~2 minutes.
Whisk in the garlic, salt and pepper.
Whisk in the Parmesan cheese until melted.
Serve sauce over or stir into pasta; add scallops.