I removed a paragraph titled "Turn off Edit when not in use", since it made no sense to me. If I missed something, please restore it with clearer wording. - RandyB February 23, 2014, at 10:15 AM
Peter, this is well written and useful. One very minor question. You ended with "Again, be very careful to differentiate between pages and scripts when you are making changes to your site. Treating one as the other or visa versa can completely mess up your system." Are you alluding to ways that admins can mess up their systems that you haven't mentioned? If so, you might want to spell those out more specifically. As it is, it's a bit general. I'm not sure if it's adding anything to what you said above it.
HansB: Perhaps it would be better to advise against any editing of php script files, except configuration files in the local/ directory, as well as any editing of files in wiki.d and wikilib.d directories.