1) System needs to be deployed across multiple servers, see: http://www.severalnines.com/blog/how-scale-joomla-multiple-servers
2) Add CSV upload to CB registration form using Fabrikar.com
For new records [unique by Name] Add query; "No records found! Does user want to create the following new records [Name/(s)]."
For new records [non-unique by Name]. Add query; "Submit 'n' records." On submit these need to be concatenated with original records.
3) Customise CB plugin "CB Ratio Field" (http://www.softforge.co.uk/resource-area/downloads/cat_view/105-joomla) to calculate a user's rank based on two other numeric CB fields. Multiple ranks per user are required after replacing the two CB fields with dynamic fields.
4) For CB1.8 profile styles, clone https://app.shipwire.com/merchants/app#merchants_account_dashboard (first login user: aaron(at)innerchina.com password: password) Refer to old CB1.1 tutorial http://www.plainlycode.com/Joomla/Simplifying-Community-Builder-Layouts.html or use http://extensions.joomla.org/extensions/extension-specific/community-builder-extensions/community-builder-profiles/7775