command logging

We are running RHEL5 x86_64 and RHEL4 (32 and 64 bit) servers mostly at work and management like to trac every single command a user types. So far we used rootsh but once a user types sudo rootsh sudo su - oracle the oracle user commands are not logged any more. Is there a way to trac/record a user to see what was typed using the audit subsystem ? We are considering the idea now to to lock root logins out The goal is to not have any shared IDs at all and all users should be identified on what they did on the servers if necessary.