To be honest I don't think my account is in 100% good standing, but I can't say for certain. There's definitely some dead comments on my account that are deserved and I think there are some small limitations that are or have been placed on it (probably fairly). Mostly around flagging and vouching.

Yeah, I have seen several people who are completely shadowbanned (all comments dead) without any visible reason. There seems to be no way to report this.