If I change a Helper layout, will it change where it's used?
No. Helpers are coupled with the page once placed. Changes to the Helper layout will not affect existing instances.
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.
Yes, this is possible by creating a custom element.
You don't. You apply a Descendant selector. These use a (Space).
Opacity is set using a decimal where 0 is transparent, 0.5 is 50% and 1 is solid.