Whisk 1 1/3 cups sugar, 1/2 cup water, 3 tablespoons tequila, 3 tablespoons orange liqueur, yolks and 1/2 teaspoon lime zest in large metal bowl.
Set bowl over 2-quart saucepan of simmering water (do not allow bottom of bowl to touch water). Whisk constantly until mixture thickens and candy thermometer inserted into mixture registers 140°, about 5 minutes total. Remove bowl from over water.
Whisk cream cheese, 1 package at a time, into warm custard until blended.
Using electric mixer, beat whipping cream, lime juice, 1 tablespoon tequila and 1 tablespoon orange liqueur in large bowl until cream holds peaks. Fold in cream cheese mixture.
Place 2 tablespoons sugar on a large plate. Rub the edges of a 14-cup trifle dish with water, or cut lime. Invert the trifle dish on the plate of sugar so that the top is covered with sugar. Turn upright.
Place margarita mix in a shallow dish. Submerge 1 ladyfinger in margarita mix, turning to coat twice; shake excess liquid back into the dish. Place dipped ladyfinger facing out, around bottom side of the trifle dish, pressing against the side of dish (ladyfinger may break). Repeat with enough ladyfingers to go around bottom side of dish once. Dip more ladyfingers and arrange over bottom of dish to cover.
Spoon 2 cups cream cheese mixture over ladyfingers; spread to cover. Sprinkle zest from 1 lime over cream cheese mixture. Repeat with more cookies dipped in margarita mix, cream cheese mixture, and lime zest in 2 more layers.
Cover and chill overnight. Before serving, garnish with lime slices.