Cut peppers in half; remove stems and seeds. Broil skin side up 4 in. from the heat until skins are blistered and blackened. Immediately place peppers in a bowl; cover and let stand for 15-20 minutes.
Meanwhile, combine the beans, tomatoes, onion, cilantro and jalapeno in a large bowl. Peel off and discard charred skin from peppers. Cut into thin 1-in. strips; add to tomato mixture and set aside.
In a large resealable plastic bag, combine the lemon juice, oil, pepper flakes, salt and cumin; add shrimp. Seal bag and turn to coat; refrigerate for 30 minutes.
For dressing, combine the oil, vinegar, lemon juice, cilantro, salt and cayenne in a blender; cover and process until smooth. Add avocado; cover and pulse just until blended.
Drain and discard marinade from shrimp. In a large skillet, saute shrimp for 3-5 minutes or until shrimp turn pink. Add to pepper mixture. Add 1/2 cup avocado dressing; toss to coat. Spoon into serving glasses or bowls; serve with remaining avocado dressing.
Wear disposable gloves when cutting hot peppers; the oils can burn skin. Avoid touching your face.