I would like to be able to do changes to www.example.com on a staging server, for instance staging.example.com. Essentially, I want the live site to be dumb, i.e. not have the administrative capabilities at all.
Is this at all possible? I've searched around for quite a bit and even though I have found similar questions, I have yet to find one that tackles this particular scenario.
Administrative capabilities are the essential part of the WordPress core, and while you may be able to block access to wp-admin directory and through this to the administrative UI, there are other ways to administer a WordPress site, namely XML-RPC and at some point the JSON API.
The easiest approach assuming all of your plugins are well behaving (grrrr unlikely) is to use a DB user which has only read permissions.
Then on your "staging" environment, assuming it is on the same LAN, you can use the same DB and table prefix to update posts data etc. One thing to keep in mind is that links in the content are likely to be different than in the production site, so some care needs to be taking about that.
You will also need to keep the uploads directory synchronized. and obviously, the code once it is changed.
Where will your problems come from with this? Anything that wants to write to the DB, comments contact forms etc.
