How do I add a combinator to my style?
You can only add combinators to child selectors. Add a child selector and combinator will appear in the Style tree.
Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
Yes, this is possible by creating a custom element.
You don't. You apply a Descendant selector. These use a (Space).
No site specific data is stored on the API.