For the salad: Preheat a grill on high for 5 minutes. Reduce the heat to medium high and grill the corn, with the cover closed and turning occasionally, until some kernels are black, about 12 minutes. Remove and allow the corn to cool slightly.
Using a sharp knife, cut off the kernels into a very large, deep serving bowl. (Hold the narrow end of the cob, point the other end into the bowl and cut downward, so that flying kernels are trapped by the bowl itself.) Add the black beans, chickpeas, cilantro, green and red bell peppers, onions, chile peppers, salt and pepper to taste to the bowl and toss.
For the dressing: Whisk together the lime juice, sugar, salt, vinegar, cumin, chili powder, garlic and olive oil in a small bowl. Season to taste with hot sauce.
Pour the dressing over the salad and toss to thoroughly coat. Let sit at room temperature for 20 minutes, toss again and serve. The salad can be made a day in advance, covered and refrigerated. Bring to room temperature before serving.