Right now without the original shots (could you post them please? I'd like to see) I'm pretty sure that the actual photos you originally took are better than the edited ones. Going to analyse one by one anyway, sorry if this sounds harsh, but it's just a few small criticisms which can be improved for future shots if taken in mind. :)
First one, quality is awkward and I can't really see anything well, special about it. What stands out? What's your focal point? What should the eyes be drawn to? If not, then you're going for something like a scenery shot which is where the editing sort of loses those details and makes the scenery strange to look at. Maybe if you went from the left and faced forward sort of, then you wouldn't have the strange view of these lines of buildings not really mixing well together. Uhh, how do I explain that, since it sounds really confusing... um, while those type of shots work well for different things, it's probably not best for buildings. Try different angles when you're only facing one building, rather than multiple ones. Actually, if that still confuses you, just take lots of different shots of different angles and see which ones work best for you.
The second image has pretty good framing imo due to the white lights leading your eyes along that way and then drawing back to the focal point which is the clock. However, the edits seem to have completely spoiled everything else. I can't really judge the colour or the lighting correctly due to probably brightness/contrast and recolouring with different layers. It's fine to have some minor edits to photography (even though I don't like the idea, but hey) but when it overpowers what the original image was trying to convey, it doesn't really help the photo.
However! The third one looks really good in terms of graphics and photography. You've used layers, etc to make the image look better to the eye, but that's really a style you'd see for an icon, not an edit of a photo. Maybe if you'd moved to the right a bit the actual main focal point would stand out more (due to how the building is situated, it would most likely look better to the eyes if you basically took away the conflicting corners (oh God what happened to my English), in other words as far as height goes, it's good, but you'd bring out the main part a lot more if it was moved left just a little bit imo at least.
As for the last one, in my opinion, the edits kind of let it down. The photo itself looks interesting, and due to your edits you lost the detail of the bottom part of the image, so all you really have is the top half, and with the light at the top, it's just confusing for the eye to be drawn to. Without the edits, though, it would look a lot more natural and the detail wouldn't be lost. Really, if the bridge kept most of its original colours and lighting the photo would be much more appealing to look at and the bridge would probably stand out better. :x
Also just going to add, you've also chosen colours for your edits that make your photography appear unnatural. That's not what you want, you want to be able to edit them so they can still keep the original colour, and slightly be enhanced with your edits, aka keep original colours, only alter the hue/lum/sat only a tiny bit if you really want, and not to overly contrast or lighten your photos. Good start though, just tone down the edits. XD