You can find the defederation info quite easily just by asking, or going to the blocked instance tab on whatever server you’re wondering about.

Your other questions are somewhat ambiguous, so there’s no easy way to simplify it into a data sheet. Because of the fact that the vast majority of instances are federated with each other, it also doesn’t matter that much.

I don’t think that kind of numerical information would really make the decision any easier, it’d be more likely to confuse people even further.

Servers are either general purpose or with a specific focus. Ani.social, ttrpg.network, slrpnk.net, are servers that clearly advertise the specific content they host and focus on. And obviously the geographical/language based servers (feddit.uk, aussie.zone, lemmy.nz) do the same thing. That’s pretty easy to figure out imho.

The distribution of joined communities just seems way more complicated than necessary. Number of users is already the most widely available stat, just go to fedidb or lemmyverse and you can easily see the list of instances ordered by monthly active users.

https://lemmyverse.net/?order=active_month

I do think a cheat sheet about defederations would be nice to have though, I might try to make one when I have a chance.

posts/second average user activity …

posts/second

posts per second

…what, are you looking for instances for bots?