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.
You don’t have to add units unless you want to use a specific unit or you’re adding Custom CSS properties.
No, the entity browser does not work for component defaults as the entities are content, not config.
Yes, this is possible by creating a custom element.
Modifiers allow you to apply styles to an element when a specific class, id or attribute is present.