Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
You can only add combinators to child selectors. Add a child selector and combinator will appear in the Style tree.
You can create more than one template to provide layout and style alternatives with the use of the template selector.
Yes, the generated templates can be saved to the database.
You don't. You apply a Descendant selector. These use a (Space).