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.
No, the entity browser does not work for component defaults as the entities are content, not config.
Not yet. The Style builder does not have the option to add an animation name or key frames. This is planned functionality on our road map.