Customise this landin page wordpress theme

I love this landing page theme by elegant themes but with one major flaw. It is only a one page theme. It is not possible to build have a second page at all which seems crazy to me. Who wouldn't at least want thank you pages etc?

http://www.elegantthemes.com/gallery/convertible/

I would like someone who is familiar with elegant themes and can demonstrate previous modified version of elegant themes they have done. This particular theme is very bespoke as it works with a page builder unique to the developer. In summary I would like to be able to build more pages in using the same page builder (available as a standalone plugin which I have the license for). I would like options for:

Full width page (same as home page)
Page with a sidebar where I can put widgets and a recent posts feed etc.
Blog page - that lists the posts of the category(s) I select like most other blog themes.

I would need to be set up as a child theme so I could run future theme updates etc.

Fran