I don't think this is a "should you have done differently." Maybe with a different day, time of day or light it might have been different. Here I think you are working with what you saw and I don't think there are too many options.. You bring out the straightness, the depth and the stone textures that are the striking features of the canal. Perhaps you could have tried a diagonal tilt but this would have looked gimmicky and your angle has more integrity.
What you might do with post processing is another matter. The sky in 1 looks a little artificial. Given the symmetry of the canal, I think the SKU might have reflected much the same symmetry. Was the darkening to the sky left done in PP? Perhaps using applied vignetting would have been a better way to add darkening to the sky while emphasizing the symmetry of the whole image? There are other dramatic lighting changes that might be made but the only things I can think of would look artificial. I think that would be a mistake as it is the cut of the Corinth that is the point and you already have it.
