I'm not an expert in night photography, but I'll give my amatuer opinion:
- I feel that the 3 photos lack punch. Maybe not bright enough or too much black. Try a low ISO i.e. 100, high F-stop value and longer exposure.
- #1 and #3 will look better if the horizontal lines are aligned to the photo. Crop abit and rotating a few degrees anti-clockwise would work
- #2 you captured the nice purplish light.