The first three all offer leading lines right to, through or in the centre of the photo, which bugs me a bit. More visual interest can be created when the lines take a diagonal (can also be rounded) path and point to somewhere in one of the "famous" spots indicated by the imaginary grid of the "Rule of Thirds".
You can get away with it in the fog photo, though. That one's interesting because of the mysterious aspect fog gives to things.
The last is not bad as far as composition goes but I'm not too sure about the conversion, I find the "sepia" colouring a bit too much - is there a chance for us to see the original (or a pp-ed pic in colour)?