You can restrict access in the ACL to specific individuals in your organisation and prevent anonymous access.
You can use consistent acl property to enforce this when a local replica or copy is made.
You can use reader fields to hide documents from (and prevent replication with) all but specified users, groups and/or roles.
You can use design access lists to restrict design elements and documents viewed with them or created from them.
You can encrypt the database on the server to prevent a file system copy from being readable.
You can encrypt documents to prevent reading by all but those who have the encryption key.
You can program the database to fail dramatically or to sneakily send notification when opened on local or on an unknown server.
You can write code to audit who reads what documents and when.
You can disable replication in the replication settings.
THE BOTTOM LINE:
You can't stop them reading the information and either
a) forwarding by an email they typed,
b) telephoning someone and telling them what they see,
c) printing it out etc
If they have to see the information to do their job then they could conceivably remember enough to benefit from your confidential information.
This is a "human" issue not a technology issue. The positions you describe are roles with responsibility, requiring trust. The complete solution will involve securing your data as best you can (without insulting the honesty of your employees), hiring trustworthy staff, making them aware of their responsibility to protect company assets, and not doing anything that would make them feel aggrieved or defrauded.
Dale
Why don't you ask the Notes Wizards at