Personal opinion and this is subjective...
Picture 1: would look better with the top and bottom cropped further so that the Buildings are almost at the top and bottom of the shot. Feels a bit too roomy. They might even work as a frame for the boat heading down the canal.
Picture 2: Great subject. Facinating however, personally I noticed that it's tilted and not symetrical. Possibly a correction in
PS would fix. that's again subjective and only an opinion. If I was submitting this one--and it's a great picture-- I'd be looking to straighten it out first.
Love Picture 5. However if it was to submit to an exhibit. I'd probabaly chose Picture 2 for the great subject matter after straightening it out