What would we need for a tracker/torrent site to exist in fediverse without danger?

As far as I understand if any fediverse instance decided to start having magnet links and stuff like that, eventually it would be taken down by DCMA notices and the like. But what could be done so a community like that could thrive?

Some questions:

1. Would other instances that federate with it get in trouble? They can always feign ignorance.
2. Could an intance which holds magnet links and trackers be backed up every day, so that as soon as one instance is taken down another one takes it's place immediately?
3. Could an instance be owned annonymously? Can you register a domain and keep a server running somewhere without repercussions?
4. Could a lemmy instance live in an onion domain, and still interact with the rest of the fediverse? Would that improve anything regarding the instance being taken down?
5. What about running instances in countries that do not enforce piracy laws? Could someone in some random country that does not care maintain an instance, which all of the fediverse can access/comment/contribute?