As a themer I like as much style control of different elements of content as possible. I have a small recommendation regarding the caption of this slider:
if ( get_the_excerpt() ) $caption .= ' | ' . get_the_excerpt();
Change this to something like
if ( get_the_excerpt() ) $caption .= ' <span class="flex-excerpt">' . get_the_excerpt() . '</span>';
I just really can use that hook so I can make the caption title look different than the excerpt. You probably have a better way of doing this but that's a quick fix.
(also the '|' is really hard to work with css wise. If you have to keep it in perhaps wrap that in a span tag as well so someone could display:none that sucker if they wanted to?)