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.
If you're removing styling from a base style, those styles still apply until you have saved the base style.
Base styles are CSS styles for HTML elements.
Yes, you can render react components.
Yes, you can add custom functionality to your site through the use of custom Drupal modules, sub-themes, and custom elements.
Yes. If you're a developer you can create your own custom elements. These will appear within the 'Custom element' category in the Sidebar browser.
Yes. If you develop your own Custom elements you can use them within Components and make their fields editable within your them.