I plan to create a mirror of my production Discourse by using the rsync method.
I have a couple of other web sites which integrate with Discourse, so having the dev/test versions of those sites being able to hit and interact with a dev/test/staging version of Discourse would be ideal.
Therefore I would only power it on when needed, and I would restore a database backup of my PROD on to my STAGING periodically - not daily and maybe as little as once per month.
If I do this, how do I stop it changing some settings back when I do the database restore? 
These for example, would be invaluable:
Is there a way I could restore a database backup and then maybe manually apply some settings before starting Discourse? Any other ideas, suggestions, gotchas?