My feedback (I'm on a work laptop so I cannot see Exif data) - please don't take this personally as it is purely my point of view!
Thanks for your comments dubaiphil, none are taken personal.
Shot 1 - an interesting viewpoint, but there's motion blur from hand holding. Also, the rail in the bottom right really detracts from the image. Leaning over the edge to take that out of frame may have helped. What would have helped further would be a tripod that allows you to lean the camera over the edge (for example my Manfrotto has a central column which can be angled). It's slight unnerving to have your precious photo equipment hanging over a ledge/rail, but a camera strap around your neck at the same time could be a form of protection from disaster. This would allow longer shutter speeds, blurring car lights, boats, water and clouds further.
I know I need to buy a good travel tripod. the only one I have is a Hama star 42 for now. It a bit big and heavy to take with you when you are traveling. I was hanging over as much as I could/dared while still being stable to take the photo.
Shot 2 - horizon in the middle of the frame goes completely against the rule of thirds, but it works here. The reason is because of the 'interesting' sky. Ideally, a graduated ND filter would help balance the exposure. Alternatively this could be done in post processing by either blending two exposures of the same image of using a ND filter plug in. We've all been up to the top of a high building to find the visibility isn't as great as we'd thought - increasing the contrast and clarity on the image in post may help here. Shooting wide (it looks like 18mm on DX here) with such a sweeping field of view can result in some distortion and the horizon's a little curved but that's not a problem really.
I will look into getting some filters and see if I can find something in post processing to make the photo better. You are right it was shot at 18mm with a DX camera.
Shot 3 - watch your horizons. There's a 'drunken' tilt here which could do with straightening. Also, when you're aiming for symmetry, being slightly out of shape is extremely accentuated. For example here, if the flower bed in the bottom of the frame is planted symmetrically compared to the lawn and monument, then make sure that's spot on and centred in the frame. This would give the image more structure and strengthen the leading lines in the frame. With leading lines in frames, make sure they are strengthened further by not having distracting elements leading the viewer's eye back out of the image. In this case you have people walking towards you on each side of the lawn, and some are cut by the edge of the frame. It's up to you as the photographer if you want 100% reality, or to edit the image slightly, but removing the structures above the treeline in background right would strengthen the composition. Judging by the 'horizon' relative to the people heads in the image, it looks as if you were taking the shot from a standing position (?). If you've got a frame like this that you think will work well, then try shooting the hell out of it. Lying down to accentuate the height of the monument, kneeling to still keep more of the back ground in the shot - just try as much as you can (if you have the time) and see what you can come up with.
Thanks for the advice about trying different positions for the shot and I will definitely do that next time. And I will look for the symmetry and try to do a better job.
Shot 4 - this doesn't do much for me, I'm afraid. Yes, there are sunbeams, but everything else is compositionally wrong. Horizon - too close to the bottom edge of the frame. Tower - too close to the left of the frame. Stadium (?) - only partly in the frame. Foreground - nothing interesting going on. Everything is leading my eye out of the image. It looks as if you have the camera on Matrix Metering, and the camera has averaged out the exposure. If you have interesting skies, which is presumably why you took the shot, then try shooting them for future use in other pictures, where you may have a bland sky that you want to replace. So shoot the hell out if it with different exposures and focal lengths so you build up a library. Avoid the cardinal sin (ever watch the film JFK, where the image of Lee Harvey Oswald was "doctored" outside his house with his rifle) of blending skies with the light coming from the wrong direction compared to the foreground though!
I did take this shot for the sky as I found it interesting with the sunbeams coming through the clouds like that. It didn't come out the way I wanted to and your tips will help me next time I shoot a sky so I'll know what to look for. So thanks for your advice it's greatly appreciated.
Shot 5 - horizons again, plus camera blur from hand holding again. Tripod plus delayed timer/remote release and spirit level would assist greatly. Manual mode or Aperture Proprity with some negative exposure compensation would also help.
I will try the aperture priority with the negative exposure next time I take a night photo. Hopefully I'll also have a good tripod by then.
Thanks for all your comments they are greatly appreciated.