@Steve: First, I see that you are using “Header Featured Image” instead of “Header Image” for logo. The best option it to user Header image for logo, you can add that from “Appearance => Header”. This Header Featured Image is for adding extra featured image like banner and all.
But if you like to control this Image then you can use the CSS ID main-feat-img. SI see that you have added the following CSS in “Appearance => Theme Options => Custom CSS” box.
#main-feat-img {
box-shadow: none; /* Remove Border */
float: left; /* Float Left */
padding-top:50px;
padding-bottom:0px;
padding-right:0px;
padding-left:50px;
}
To center you need to remove float: left; /* Float Left */ and padding-left:50px; from the above css. Since, you are not using Header Image and site titles you can hide that by adding in the following css
#hgroup-wrap { display: none; }
.
