For music. I use navidrome. It works a load better then jellyfin for this IMO. You can use the same file location for both jellyfin and navidrome if needed.
It not only hurts tor because it usage up bandwith but in other ways as well. Torrenting makes many peer to peer connections which hurts tor in multiple ways. I suggest reading the docs of tor to better understand how and why this is.
I dont understand your question about I2P. You need some form of I2P router to use I2P in anyway.
I have used SAP extensively. The issue is SAP can do soo soo much more then many ERP systems in regards of finance. It is a nightmare to use but one of the only systems capable of what it does. Also it doesn't help that it is over 50 years old at this point and companies are stuck with it. It is no easy task to migrate that kind of data.
Sounds like you are a data hoarder haha. Can't blame you. But for such hobby's perhaps a ZFS system with deduplication and a second ZFS system to use for backup of the first system is what you want.
That is with any piece of software. their will always be some vulnerabilities that are very bad. so by your definition using any piece of software is a concern.
For such a setup I think it Is a good idea to look in to freeipa/idm. Would make management a load more easy. centralized account control and being able to sit at any PC and login with your own credentials is one of the many benefits.
I mean blow out of proportion nowadays yes. But this wasn't the case just a few years ago. We have come such a long way to make it almost a simple click install. But dont forget where we came from.
So their is some truth to it although its mostly outdated now.
While coming up with such flawed laws as well. I doubt they even look at the feedback