Our moderation policy can be found here: https://post.lurk.org/terms
Mastodon has quite granular visibility settings for your posts, you find them in the message compose field. Here is how they work: https://dev.glitch.social/@cassolotl/99942225799392803. In addition to those we have another option (the chain link) which makes your posts not federate, meaning they are only visible on post.lurk.org.
It is possible to switch to different color themes and even a multi-column layout in your preferences: https://post.lurk.org/settings/preferences/appearance
If you want to move to another instance you can migrate your social graph here: https://post.lurk.org/settings/profile
If you wanna do some serious reading on what else is possible, here's a good place to start: https://github.com/joyeusenoelle/GuideToMastodon
Welcome to post.lurk.org, an instance for discussions around cultural freedom, experimental, new media art, net and computational culture, and things like that.