There isn’t any padding in the slideshow, any you’re seeing on your site is due to the theme, probably just on the container that the slideshow is in.
You can change the navigation graphics using a custom stylesheet, just reference different images in your theme instead for the background images of the nav and change the sizes accordingly.
The pager navigation is absolutely positioned to the left, you can switch this to the right, and change the width to auto to move it to the right:
.meteor-slides .meteor-buttons {
bottom: -15px;
height: 9px;
right: 0;
margin: 0;
padding: 6px 0 0;
position: absolute;
width: auto;
z-index: 999;
}
If you want to use a caption like the demo, you can do that using a custom slideshow template.