I think the important thing is to be realistic about how much you can expect your non-technical users to do. Your job is to only give them access to the things

I think the important thing is to be realistic about how much you can expect your non-technical users to do. Your job is to only give them access to the things it makes sense to let them touch. For example, in drupal, it's probably a bad idea to give them the ability to edit blocks, but you might let them use promos or panels. If there's something it's not realistic for your users to do, then either you have to take responsibility for doing it, or you have to exclude it from the site. Having said that, I'd recommend wordpress or drupal as they seem to be the cms's with the most active development around them.