Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
Base styles are CSS styles for HTML elements.
Custom styles are CSS styles for classes.
No, there is no way to roll back an Acquia Cohesion package import.
With Acquia Cohesion Sync you can export Acquia Cohesion configuration in full or in part as a package that can be imported into a different website.
An Acquia Cohesion Package file is a .yml file that contains Acquia Cohesion Configuration. The package file allows you to import and export between environments.
HTML is escaped when using Drupal tokens in Site studio as a security measure, this follows Drupal core.