Place roast in a 3-qt. slow cooker. In a small bowl, whisk lime juice, marinade mix, sugar and oil until blended; pour over roast. Cook, covered, on low 6-8 hours or until meat is tender., For salsa, in a small bowl, combine corn, beans, tomato and jalapeno. Stir in lime juice, oil and seasonings. In a small saucepan, combine sauce ingredients; cook and stir over low heat until blended., For crostini, preheat broiler. Brush bread slices on both sides with oil; place on ungreased baking sheets. Broil 3-4 in. from heat 1-2 minutes on each side or until golden brown., Remove roast from slow cooker; cool slightly. Shred pork with 2 forks. To serve, layer toasts with salsa, pork and cheese. Top with sauce. If desired, serve with lime wedges.