I like fpmurphy's ideas. It sounds like you're trying to create a "shell for unix dummies", which is also a good idea, but completely different than what fpmurphy is talking about. Also, your idea can be handled very simply as extensions to zsh. What else did you have in mind besides "command not found" and of prompting users with helps and tips?
Speaking of providing user tips, is there a database of command-line tips, formatted for use by "
fortune" ?