You can filter out unwanted syslog messages using the no logging message [syslog id #] Or you can change your logging level to reduce your logging. I have found the no logging message command usefull in cases where I am required to log certain messages that I can only get a debug level, and don't want all the other stuff you log at that level.
You can adjust user privileges to assign varius levels either from the command line, or from the Pix device manager. Unless your a typing freak, it's more easily done from PDM.
Config change monitoring is easily done by implementing a radius or tacacs server and AAA, or by buying CW2000 VMS and managing the PIX's with the firewall mc. This would also take care of your syslog management problems at the same time.
