Combine the cream cheese, Cheddar, hot sauce, Worcestershire sauce, garlic powder, onion powder and shallots in a large bowl. Beat with an electric mixer until thoroughly blended. Season with salt and pepper. Transfer to a large sheet of plastic wrap, cover with a second sheet of plastic wrap and form into a football shape. Wrap up in the plastic and refrigerate until firm, at least 2 hours and up to overnight.
Preheat the oven to 350 degrees F.
Combine the butter, rosemary and thyme in a small bowl and microwave until melted.
Lay the crackers out on two baking sheets. Brush the tops with about 2 1/2 tablespoons of the herb butter. Bake until fragrant and a shade darker, about 10 minutes. Cool completely, then store in an airtight container at room temperature until ready to eat. (The crackers can be made up to 2 days ahead.)
Toss the walnuts with the remaining herb butter and arrange on a baking sheet in a single layer. Bake until golden brown, about 8 minutes. Cool completely, then finely chop.
Unwrap the cheese ball and cover completely with the walnuts. Transfer to a serving dish. Separate the string cheese into strands and arrange them to look like the laces on a football. Serve with the herbed crackers and crudites.