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.
Yes, you can use Drupal fields in certain parts of Acquia Cohesion.
The 'Range' in the menu list item element sets which list items at the current level the settings should apply to.
It depends on the use case. For fields and their field formatters use a 'Field' element, for data without field formatters, use a token.