1. 'Backups Management' functionality is not able in Rackspace next generation servers.
2. Bandwidth Billing Functionality works same as Disk Space and Bandwidth Overage Billing. Here you can find more information how to configure it.
3. Bandwidth Billing Functionality works with Rackspace next generation servers only.
4. Bandwidth Billing Functionality is implemented inside the Rackspace Cloud Servers For WHMCS module and it doesn't have external display place in the module interface.
5. Details of the server are updated only when the page is refreshed/loaded/reloaded. This operation is complex and requires 4 queries to the server, so when you refresh or reload a page 4 queries are sent to the server.
6. BW value is displayed at order page after running CRON.
7. Your customers can view their current disk space usage and bandwidth usage at their clientarea in 'Product Details' section. You can monitor those values at your WHMCS -> 'Client Profile' -> 'Product/Services' .