I was thinking more from a backend management perspective rather than the end user's. As you say they will be restricted on what the can and can't do and really should be responsible for their data. There again end users can always manage to find ways to break something, given half a chance.
My recent experiences of broken CMS software has made me very wary about how I approach development with CMS platforms. My method to date has opnly involved non-database driven sites. So I simply back everything before I replace any files. If I find the changes break the site I simply replace the files with the backups. It normally only taks a few minutes at most.
I've got a lot to learn.
Thanks for the feedback, Graeme. Much appreciated.