Thank you for your comment, and yes, this certainly helped

I shot all of these photos on "the go" and unfortunately didn't have time to set up a tripod, hence the blurriness in #1. When you say that the sky is lacking in intensity, what do you mean? Do I need to make it more colorful?
#2: Unfortunately the truck got in frame just before I shot it. I focused on the buildings as I was on the move, and didn't notice until later.. And what is tonemapping?
These shots were all taken within a week of purchasing my first camera, so thanks for the critique!