I can only offer general commentary. To me this doesn't read like content-addressed-media, it reads like media relaying since it doesn't address longevity of storage. Or does it?

For the choice of infohash (sha1) - why not sha256?

We can expect to live in a world of deep fakes soon, so I would also consider pgp signatures instead of pure integrity hashing.

The syncthing community may offer clues into operational aspects of a data relay network (relays.syncthing.net).

I looked up some sizes of large data centers today:

Library of Congress - 3 PB

github - 18 PB

Internet Archive - 100 PB

Youtube - 300 PB

My most substantive feedback is to consider PGP signatures and integrate that with nostr keys. Hope you find it helpful, Cheers 😀