Yes, you can just use the seedbox to download and run jellyfin locally with the media staying on your box, but it might be a lot easier to just get a seedbox that allows you to run jellyfin on it.

If used them a few times before tools to rip from streaming services became as common as they are now and thkse releases are fine. Dont really see a reason to use them nowadays tho besdies the scenes seal of approval.

Also I get your frustration with people not understanding what you mean with “scene” here, but tbf you could have specified which scene, in this case it would be the warezscene that you are talking about.

For those unaware about the warezscene, they are the groups that make releases for every type of media and are bound by rules (you can look them up if you wanna know specifics about those), the names the op mentioned are a result of those rules.