Place the shrimp into a mixing bowl. Add 2 tablespoons of oil, 1 tablespoon of salt, and the spice blend. Toss well. Cover and marinate in the refrigerator for 30 minutes. Transfer the bowl to room temperature and let sit for 10 minutes before grilling.
Meanwhile, heat the grill over high heat. Coat the corn and pineapple slices with a drizzle of oil and a pinch of salt. Grill both for a few minutes until charred on all sides and tender. Remove from the grill. Chop the corn and dice the pineapple, removing any hard core sections.
In a large mixing bowl, whisk together the ranch lime dressing.