I am glad you like it! And thank you for the feedback.
I have not been very restrictive about the topics because I prioritize giving people a safe space in the fediverse to build their communities, even at the cost of some dilution. But, if the consensus that staying in focus is important, I am willing to enforce a more strict policy about the topics of communities - in that they at least have to be related to science/nature.
I would much rather not restrict the creation of communities to admin-only. I prefer people to be able to create the communities that they want. At this time the volume is low, so I can manually inspect the communities after-the-fact.
I still have not written a more detailed policy about the server. There were not many users, so that was a good excuse to procrastinate. It may be important that I actually set some time to write some ground rules - so thank you for helping me coming up with them.