Heat griddle to about 375-400℉. *If cooking shrimp fajitas on the stovetop, preheat a large skillet on medium heat.
Make the tequila-soaked pineapple. Place the pineapple rings on the heated surface and grill on the first side until you see some browning and char. Then flip to the second side and continue to cook until lightly browned. Transfer the grilled pineapple to a cutting board to cool slightly, then dice into "tidbits" size. Add the diced pineapple to a medium bowl with 2 tablespoons to ¼ cup tequila. Mix together and set aside.
Make the shrimp basting sauce. While the pineapple is cooking, start the melted butter sauce for the shrimp. To a small saucepan, add ½ stick butter, 3 cloves minced garlic, ½ minced jalapeno, juice and zest of ½ lime, and ½ cup tequila. Heat the saucepan on the griddle to allow the butter to melt and the flavors to incorporate.
Season the shrimp. In a small bowl, mix together 2 tablespoons of all-purpose seasoning with the smoked paprika, chili powder, cumin, and ground coriander. Sprinkle the seasoning on the shrimp and set aside. *Taste your seasoning for saltiness (varies depending on which all-purpose seasoning you use). You may not need to use all of the seasoning mix.
Make pico de gallo. In a medium bowl, mix together 3 diced roma tomatoes, ¼ diced white onion, ¼ cup chopped cilantro, 1 clove minced garlic, juice of ¼ lime, ½ minced jalapeno, and pinch of salt. Use a slotted spoon to drain the tequila-soaked pineapple and add the tidbits to the pico de gallo. Mix well and set aside. (You don't want to add the extra tequila to the pico because it will be too overpowering. You can pour the excess tequila in the saucepan with the melted butter if you wish, or add to the shrimp as they are cooking on the griddle.)
Cook the fajita vegetables. Add about 2-3 tablespoons of high heat cooking oil to the heated griddle surface and spread it around with your spatula. Add the sliced bell peppers, onions, and jalapeno to the oiled surface in a thin even layer. Allow to cook untouched for about 2-4 minutes for the vegetables to develop a bit of char. Season vegetables lightly with all-purpose seasoning or salt and pepper. Then, sauté together until about 50% cooked through. When peppers and onions are 50% cooked through, add the tomato wedges to the griddle. Cook for 2-3 minutes to develop some color on the tomatoes, then mix with the fajita vegetables. Move the vegetables to the cooler side of the griddle to make room for the shrimp.
Cook the tequila lime shrimp. Add about 2 tablespoons of high heat oil to the griddle surface and spread around with your spatula. Place the seasoned shrimp on the oiled surface, making sure that each piece lays flat on the griddle to develop some char. Add about 2 tablespoons of the butter mixture over the shrimp. Cook the shrimp on the first side until about halfway done, about 4 minutes. Then flip to the second side, and add the remaining butter mixture. Continue to cook shrimp until done.
Serve the tequila lime shrimp fajitas. When vegetables are cooked to your liking, transfer to a serving platter. Top with the cooked tequila lime shrimp. Squeeze additional lime juice on top if you wish. Serve the fajitas with flour tortillas, pineapple pico de gallo, sliced avocados, and your favorite fajita toppings.