I haven't looked at a production alert.log file in about 3 years. I would advise you to learn which entries in the alert.log file indicate "trouble" and then write some scripts to monitor for those trouble events. Monitoring of the alert.log script can be automated with simple OS tools and mail.

Your monitoring scripts don't have to give you every detail of what the problem is. If I get a page saying that I have an ORA-600, I will go into the alert.log and investigate.

Whenever I install a new version of Oracle (in test, of course), I monitor the alert.logs RELIGIOUSLY looking for new "trouble" events. If a new event is found, I update my scripts and never worry about it again.