If you run a public relay, why not I guess. It could help people like nostr:npub1sn0wdenkukak0d9dfczzeacvhkrgz92ak56egt7vdgzn8pv2wfqqhrjdv9 or any other anon to connect privately to public relays.

Yes, if you have the bandwidth to spare. It'd be wise to stick to entry and middle nodes. Exit nodes can potentially get you in trouble with the law.

If setting up a node is too complicated for some or you don't have a system to run it on, the Tor Project has a browser extension that lets you run a Snowflake pluggable transport in your browser, which helps people circumvent censorship. That's what I do, since I dont have a spare system that can function as a Tor node.

Did you mean a TOR relay or a nostr relay as an Onion service? I automatically thought you meant the latter😅