I've just purchased "Elegance" theme for VSD and I started to build my site. Is there a simple way to exchange the original title (Elegance" Established in 2010) with my own logo or title on all pages at the same time?

Stirs up a hornets nest :: but one very tiny issue in VSD is simplicity.

Unfortunately at the expense of your request, once you have a design your happy with on home page, its a case of picking up elements to carry through to every other page, with the shift key held down, and then pasting into all the other pages individually.

That said, if you create a master page :: called something like template, you can use that to make all your pages, (use pages tool, select copy template page) identical and then remove unwanted sections to put in your new content.

So best get design right before making 30 or 40 pages.