Most notes admins keep a second copy of all ID files and their passwords. In R4 one way of this automatically is by creating a user called 'Escrow Agent'. All new id files will be sent to this users account along with their password.
In R5 the Escrow Agent does not work the same way. What you have to do is go into the administration client and in the configuration tab you can 'add recovery info' to the certifier ID file. Then when new id's are created using this certifier the id file will be sent to the account specified while adding the recovery info.
In answer to your question about recovering the data, you can indeed open the database on the server and add somebody else into the ACL but any documents that were encrypted with the original ID file will not be recoverable.
Hope this helps.
Declan lynch.