Does Internet Archive have a distributed residential IP crawler program? I would enthusiastically contribute to that.

There must be some mechanism to prevent tampering in such a setup.

The Internet Archive does not, but Archive Team does: https://wiki.archiveteam.org/index.php/ArchiveTeam_Warrior

No, IA does everything above board and even honors invalid DMCA takedowns.

> There must be some mechanism to prevent tampering in such a setup.

Trivial as long as they terminate the TLS on their end, not yours. So you'd just be a residential proxy.