CIRCLE WITH A DOT

@mdiluz for now, look at the draupnir documentation, especially the protections list and concepts, like policy lists. It begins here
https://the-draupnir-project.github.io/draupnir-documentation/moderator/setting-up-and-configuring
About power levels and join rules, that stuff is mostly learned by doing, I dk of any well put together resource for specifically this, but as I said, those are kinda hacky and that's more of a last resort thing, use powerlevels and join rules responsibly, but most of those mechanisms should be performed with your moderation bot of choice. If you want certain features or need help with something you want to do but don't know how, feel free to go in the community, the draupnir room is public and available even in the matrix.org room directory, but I can provide a link if you can't find it on the site or in the directory

@mdiluz alright, so I'm gonna point out a few things about matrix in here, which are a bit wrong or inaccurate.

First, you don't have to host the full history of a room whatsoever, that'd require huge storage which I don't have for one, and neither would probably a lot of the people hosting matrix homeservers today. In theory all events are duplicated, but in practice all events from the point of joining only are duplicated, and old events, especially media because that's the biggest stuff in your matrix installation, can be forgotten from the room representation depending on the server. Also depending on the server, you can have a very space and memory efficient server if you're looking for that, and in that case I recommend continuwuity, but do note that you will lose some features specific to synapse if you go that route. So no, you don't have to defederate or avoid federation, however avoiding open signup is recommended indeed, because if you don't, spammers would easily overwhelm your server and use it as a spam vector, which will make the whole server appear on blocklists, like here on the fedi.

Second, calls. Yeah...that's a bit of a sore spot for sure, we have two standards, but everyone pretty much agrees that the first one is the legacy standard because it wasn't really good. The second one keeps evolving because it's an actual rethink of the whole thing, which takes time to get right, but element, gomux and probably some other clients here and there support it in its current form, even if a new major version of that unstable MSC which remodeled some of the transport again exists and the reference implementation is migrating to it.

Third, moderation, well I'd say we actually have it better than discord in many cases, because we rely on the federated nature of matrix, and then external and swappable tooling for moderation, essentially bots, and we also have another powerful thing called policy servers.
There's a lot one could say about how it works, what policy lists are and how we deal with spammers, but I think the documentation of the draupnir project, which is the moderation bot a lot of people use, explains this stuff quite well.
Another thing you mentioned is scoped permissions, well that's what power levels are for. You can modify the state of a room, so that a specific power level is required to send a kind of event, and critically, any event. can be restricted by that. That way, you can have telegram stile channels, rooms in which people can't start voice calls, stuff like that. In this also go the join rules, which instruct a server in what circumstances a person can join a room. This could be something like, you can't join this room unless you were a member of another room specified by the person who makes the rule, most often this is used to limit rooms which are part of a space, like a discord server, to be only joinable by the people in that space, but that's not the only use.
Sure, all this sounds complicated, but I'm saying this stuff exists, we just need good UI for it and that's challenging. But also, I think we don't really need the roles thing in matrix, because we can split our space into as many subspaces as we want, and then invite the people who should belong to a specific subspace straight there, because spaces are just rooms at the end of the day. It also helps that once a person is joined to a space, they aren't automatically joined to all rooms the way they're joined to all channels @everyone has access to on the discord side for example. So yeah, the thinking is slightly different here, but I think it's a bit better and more organized, I might just be biased though which is definitely a thing that can happen