The Help Center have a section titled What topics can I ask about here? It is still empty, but it should list which questions are allowed, and which not, in the same same it does the equivalent section of this Stack Exchange site.
What questions should be listed as off-topic, for esperanto.stackeschange.com?
Over the years, we've found it generally more helpful to forgo these all-encompassing scope/rules discussions in favor of talking about very specific problems when they come up in actual practice.
This site is about Esperanto. I would begin your days embracing a broad range of interests so we don't start off by flogging newcomers with a patchwork of what on and off topic on this site.
In other words… let's not be too quick to jump on hypothetical problems until they become somewhat unworkable in actual practice. We have found that avoiding these forced rules discussions has worked exceedingly well for our newer sites; it makes for a much friendlier community overall. We may eventually need to enumerate some bullet points regarding what's on topic for the "help center", but it is way too early for that.
If you have a specific concern about something you're seeing on the site, please feel free to post a separate discussion about it here (on meta); but for now, I am going to close this thread as 'too broad'.
Off the top of my head:
