Do I have to use IMCE?
No. Acquia Cohesion allows the site builder to select, either use of IMCE or Entity browser for browsing and selecting images.
Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
Yes. You should revision your Acquia Cohesion assets like other configuration using a service like Git.
The style preview may not be updated because the refresh icon hasn't been toggled to the active state.
HTML is escaped when using Drupal tokens in Site studio as a security measure, this follows Drupal core.
Cohesion layout revisions are created at the same time as node revisions, but not always deleted at the same time.
Use the "Node Revision Delete" contributed module to manage your node and associated Cohesion layout revisions.
Use the tools included in the "Entity Reference Revisions" contributed module.