Staging should be the same setup as your live server. Call the environments what you will but its typical to have dev, test, staging and live. Dev being your local machine, test, staging and live are all exact replicas of one another residing on different servers. So if your production setup is a web farm your test and staging environments should be as well, otherwise its pointless to have them. The whole point to having these environments is to minimize risk when publishing code changes.
You can have your content editors do what they will on the production site, and use workflow to publish those content related changes. Then for your development environments, turn on Content Staging. This will keep track of your changes within Kentico from an object standpoint and allow you to sync them from one environment to another. I've even worked with clients that ONLY do content changes on their staging server and always use Content Staging to push them to production after the workflow process.
There are different ways to do this but if you're going for a HA/DR setup, you will want at least another instance exactly like your production instance.