For the shrimp: Soak 8 bamboo skewers in water, if grilling over an open flame (or use metal skewers).
Begin by making a quick marinade. In a large mixing bowl, combine the tequila, cumin, paprika, cayenne, garlic, lime juice and a little canola oil. Add the shrimp and toss well to coat. Sprinkle with salt and pepper. Take the skewers and thread 4 shrimp per skewer.
Heat up a grill, grill pan or flat top. Place the shrimp skewers on the grill and cook until pink, well-marked and nicely charred, 40 to 50 seconds. Remove from the grill and set on a large platter. Add the cilantro and finish by squeezing the lime wedges for some fresh lime juice all over (while the shrimp are warm they will soak up the lime flavor).
For the spicy pink mayo: Combine the mayonnaise, Mexican crema, lime juice, agave, chipotle and adobo sauce and some salt in a mixing bowl. Refrigerate until ready to serve.
For the tacos: Take a large nonstick saute pan (or on a flat grill top) and spray lightly with some nonstick cooking spray. Warm a tortilla for about 30 seconds on both sides, and then lightly coat one side with a sprinkle of Parmesan. Warm through, and then flip so it toasts cheese side down. Allow the cheese to cook and brown about 15 seconds, and then remove from pan. Repeat with the remaining tortillas.
To assemble: Place a skewer of shrimp on a doubled-up tortilla (cheese side up) and remove the skewer to leave the shrimp lined up in a row. Top with the diced tomato, iceberg, Cotija cheese, spicy pink mayo, lime and cilantro. Serve with beans.