The spice rub and dipping sauce are hot, hot, hot (but quite good). Serve with slices of cucumber and fresh cilantro leaves for a cooling effect in the mouth. Thai chiles are very spicy, so you can use fewer (and increase the mild bell pepper) to tame the heat.
Score squid by making 4 (1/2-inch) crosswise cuts in each tube.
Combine bell pepper and next 4 ingredients (through ginger) in a food processor; process until finely ground. Stir in sugar, soy, black pepper, and salt. Combine squid and 2/3 cup chile mixture in a large zip-top plastic bag; seal. Marinate in refrigerator 3 hours, turning bag occasionally. Reserve remaining 2/3 cup chile mixture for dipping sauce.
Preheat grill to medium heat.
Remove squid from bag; discard marinade. Arrange squid in a single layer on grill rack coated with cooking spray. Grill for 2 minutes on each side or until charred and squid begins to curl around edges. Serve with reserved sauce.