Can I suggest a DEFCON system? Whereby DEFCON 1 blocks all PMs, replies to comments / posts, replies to replies to your comments, etc. all the way up to DEFCON 5, where users may only be filtered from view in feed / global / chatter / globalchat? On the spectrum of "control given to the user", it removes a lot of the customizability of how I block / ignore someone. But I think it would be safe to say that if I don't want someone PM'ing me, then I probably don't want them replying to my threads nor do I want to see their posts. It might also simplify the current system, as I think a few people have noted that "filter" / "hush" / "mute" are not quite as intuitive in meaning as we might hope...
Sorry I misread your DEFCON 5. I thought that meant that they would be filtered from view in global for everyone (total world nuclear war). That being said, most of that seems accomplishable just by tweaking the existing mute/filter/hush system.
Yes, just we're getting to the point of too many options, which I recall a few of the admins mentioning they wanted to avoid. Plus the added factor of being able to declare DEFCON against people (which is probably a negative, since I don't think the admins want us unnecessarily going nuclear)