The homepage banner is not centered and requires a bit of coding.

This would involve setting a wrapper to 100% and the banner size inside to fixed with a max-width and auto margins. I would also apply these changes via the overide system.

Example Code:

#homepage-slider {
  padding-left: 0;
  padding-right: 0;
  margin-bottom: 14px;
  max-width: 100%;
  max-height: 100%;
  overflow: hidden;
  position: relative;
  z-index: 1;
  float: left; }
  
@media (max-width: 767px) {
	#homepage-slider {
	width: 100%;
	max-width: 100%;
	padding-top: 20px; }
}
	  
#homepage-slider #homeslider {
	margin: 0 auto;
	padding: 0; }