Sounds like you have it figured out. Although i've not tried it myself, i think that may work in reverse for adding pages.
However, you may find it easier to just recreate the site in Site Sculptor. You can add/remove any pages you like from within the Site Type interface. You can also create the Site Type that works best for you so that creating sites in the future is even easier.
An alternative, that would give you the add/delete functionality you are looking for is to purchase a copy of PowerCMS 2 and upgrade your Site Sculptor CMS with that. We have a tutorial on how to do that here:
As for the sitemap page, the existing content is just placeholder in this version of the product. You will need to use the CMS to manage that content and add the links that you need. In a future release we may make this more dynamic so that the sitemap page is populated for you.