Combine marinade ingredients (except chicken) in a small bowl and whisk until well combined. Pour marinade into a large ziploc bag and add chicken. Press out as much air as possible and marinate in the refrigerator for at least an hour.
Mix salad dressing ingredients together in a small bowl, cover and refrigerate until ready to use. Taste and add more chili powder if needed.
Once the chicken is ready to cook, heat a grill pan (or your outdoor grill) over medium heat. Rub olive oil on the grate to keep chicken from sticking. Place chicken on the grill and sprinkle the top side generously with salt. Cook chicken about 4 minutes per side, until no longer pink in the center. Transfer to a cutting board and cool for 10 minutes before slicing.
Meanwhile, heat 2 tablespoons olive oil in a large, heavy bottomed pan (such as a cast iron skillet) over medium-high heat. Cook peppers and onions, seasoned with juice from one lime, salt, pepper and about 2 teaspoons of chili powder until barely limp; about 6-7 minutes. Add corn and cook for another 2 minutes. Set aside to cool.
In a large mixing bowl, toss salad with sour cream dressing. Divide into bowls and top with chicken and veggies. Serve with lime wedges.