The standard JSON component will return the images for the banner.
The design mode of the CMS is the standard page/URL with an additional parameter DESIGN_MODE. The system checks if the user has CMS access and then will show the site in design mode.
The system administrator can configure the system password management and storage options to find the correct balance between convenience, performance and security. The password and login options can be configured at the global level and at a per user level.