Lemme rewrite that for the plebs reading the comments in this thread.
JOINSTR is COINJOIN OVER NOSTR
I know its confusing still for the non-technical plebs 
, but evolutions will come soon. Pay attention to nostr:npub1v6qjdzkwgaydgxjvlnq7vsqxlwf4h0p4j7pt8ktprajd28r82tvs54nzyr
This page has several pieces of incorrect information
Tor is required if you cannot trust the relay, which is most likely the case
A mechanism without fidelity bonds would require you to tie your Nostr identity to your CJs as the fidelity bond (not preferable)
1. Protocol supports VPN and Tor. It's not necessary to use Tor. You can check the kotlin implementation for VPN usage.
2. Joinstr protocol will use AUT-CT for sybil resistance: https://github.com/AdamISZ/aut-ct?tab=readme-ov-file#worked-example
If you read the NIP for joinstr you will realize that new keys are generated for each event and pool messages use encrypted channel (shared key).
Nostr identity is never linked to coinjoin in the protocol.
It is also possible to reuse fidelity bonds if some joinmarket makers want to provide liquidity in joinstr, not necessary though: https://uncensoredtech.substack.com/p/market-makers-in-joinstr
