Place sugar in a small saucepan over medium-high heat; caramelize by stirring often until sugar melts and is golden (about 2 minutes).
Remove from heat; carefully stir in grapefruit juice and 2 tablespoons lime juice (caramelized sugar will harden and stick to spoon).
Place pan over medium-high heat until caramelized sugar melts. Bring to a boil, and cook 8 minutes or until reduced to 1/2 cup. Remove from heat; stir in 1/8 teaspoon pepper.
Set aside. Coat a nonstick skillet with cooking spray; place over medium heat until hot. Add bok choy and onions. Saute until bok choy wilts. Combine bok choy mixture, 2 tablespoons lime juice, and next 5 ingredients (lime juice through crabmeat); stir.
Working with 1 egg roll wrapper at a time (cover remaining wrappers to kee from drying out), spoon 1/4 cup crabmeat mixture into center of wrapper. Fold lower right corner over mixture; fold lower left and top right corners over mixture. Moisten top left corner with egg white; roll up jelly-roll fashion. Repeat procedure with remaining wrappers, crabmeat mixture, and egg white.
Heat oil in skillet over medium-high heat. Add egg rolls; cook 5 minutes o until golden, turning frequently. Arrange 1/2 cup salad greens and 3 grapefruit sections on each of 4 plates; top each with 2 egg rolls. Drizzle 2 tablespoons caramelized sugar mixture over each serving; sprinkle each with 1-1/2 teaspoons nuts.