Hey there. If you add the following to your custom.css (or wherever you want for that matter), the thumbnails should be centred.
.thethe-image-slider-thumbnails {
position: relative;
float: right;
left: -50%;
overflow:visible !important;
}
.thethe-image-slider-thumbnailsunder {
overflow:visible !important;
}
.thethe-image-slider-thumbnails-inner {
position: relative;
left: 50%;
}
.thethe-image-slider-thumbnails-thumb {
position:relative;
float: left;
}
I've only tested in the latest Chrome though. The technique used is from http://www.pmob.co.u...ntred-float.htm. Hope it provides a starting point at least. It's always hard to dig through the rubbish code that the plugin generates (so many 'the's!!). As for the shortcode in the excerpt, I haven't found a solution, but the fault is obviously either with the popular widget code or the gallery plugin itself (but I guess that's nothing new).