It would be really useful if the GUI could be changed be more "project/solution" oriented. As most of the time I want to use some templates as background, I have to have multiple tabs just for the templates and then another set of tabs that reuse the templates (ending up with too much tabs).

Ideally we would have: - a tree-like approach to show the available "pages" with the ability to organize pages in folders/sub-folders - Not all pages would be kept open in tabs, using tabs (TDI) with a close button.

I agree... or at least a search for tabs.... or a way to reorder the pages using drag and drop.