How to change roster status for all users at once, so they dont have to request authorisation for all contacts. . .
If you are looking to have a prepopulated roster you need to create a group add the users to the group, then share the group. This doc will help with group sharing: http://www.igniterealtime.org/community/docs/DOC-1619
If you are talking about eliminating the nags to allow roster additions, you need to install the subscription plugin, and configure it to allow local.