They are replies not comments so they are notes themselves. Why should you be allowed to censor someone else's notes

you just need to set a trust level threshold on what notes you will see

Definitely a problem, not everything is about censorship.

https://media.poster.place/a46f2d3c1f66e7cdaacc3e6fd652c5bb189279435268395d399e07465c62d3e4.png

One practical solution is to build personal relays into clients where you can block people from downloading your content and comments. If you block an nsec, the relay would refuse too send or receive any messages from them.

(a) mute them (b) use Web of trust (c) only use permissioned relays (nuclear option, at that point you might as well just be on Mastodon)

To understand why this is not possible, you have to understand what a regular note is, and what a reply is on Nostr. When you create a regular note (kind 1), your client attempts to save that note to whichever relays you have listed as your "write" or "outbox" relays. Those relay operators may have...