If you store it in compressed chunks (or on a file system that supports compression, I guess), that should be a great deal smaller, being text only.
They supposedly never delete good stuff, just make it unavailable, as you said. Maybe we'll get them in a hundred or so years!
ArchiveTeam's uploads also don't have torrent files (anymore). Their wiki says that they disabled it to lighten the load on IA's servers, as creating a .torrent file for a 10+GB upload takes considerable time, especially if it has to be redone.