I had already installed Version 2 of the slideshow on one of my sites, and when the thumbnail strip would become full, it creates a second row of thumbnails under the main one (on TT template)! This is why we had to limit the number of slides per slideshow on this site. 
I now want to install the new version of the slideshow on a new (Pottery) website.  The site owner naturally expects to place as many product slides as she likes on a given collection(slideshow). Would the thumbnail strip work without automatically creating additional rows (which would look bizarre as you can imagine!)? I want to use the TT template again. In fact may question also applies to any slideshow template.

Hi. This depends on the template. However, you can try to tweak one of the existing themes or create a new one. Of course this requires that you are familiar with Joomla! HTML and CSS.