Place chicken in the bottom of your slow cooker, season with salt and pepper.
In a large bowl, combine the cream cheese with the salsa, lime juice, cumin, chili powder, cayenne, onion powder, garlic, cilantro, and scallions. Pour over the chicken in the slow cooker. Cover and cook on low for 4 hours, or high for 2-3 hours, or until the chicken is cooked through and easy to shred. Use two forks to shred the chicken and mix with the sauce, the stir in the shredded cheese. Keep warm.
Preheat the oven to 425 degrees and spray a baking sheet with cooking spray.
Spoon 2-3 tablespoons of filling onto the lower third of each tortilla, and roll tightly. Place seam side-down on the prepared baking sheet. Repeat with remaining tortillas and filling.
Spray the taquitos lightly with cooking spray. Bake 15-20 minutes, or until the tortillas are crisp and golden-brown.
While the taquitos are baking, you can mix your salsa verde and ranch dressing together, and serve alongside the taquitos.