You have a lot of different suggestions here, the latter of which have not been implemented so I will leave the topic open, but I wanted to let the thread know that we have recently released the ability to remove followers from your list by Blocking them.
You can see how to Block a user here: https://help.twitch.tv/s/article/how-to-manage-harassment-in-chat#BlockWhispersandMessagesfromStrangers
Additionally, you can see your channel Banned Chatters in your Moderation Preferences in the Dashboard
An error occurred while saving the commenthijinks commented
Please allow this, I feel that it's long overdue and very necessary.
I would like to add that if a broadcaster has banned or ignored a user, that user should NOT be able to have notifications of that streamer going live in ANY way. My stream thumbnail, etc should not show on a user's Following - Live channels section, they shouldn't receive emails or push notifications or any other notifications at any time if I have banned and/or ignored them. In fact, since Twitch won't implement cutting the stream off for them completely because the user could just log out to watch, the absolute only way a banned/ignored user should be able to visit a channel they're banned/ignored in is by direct link. Not by recommended channels, not by notifications; nothing else. If they want to work that hard to troll by just logging out or into another account, they should have to remember and enter the entire direct link themselves. We should absolutely be able to disappear into the shadows to anyone we ban or ignore. And since twitch hides a banned or deleted channel from their follower's lists and then shows it again when the channel is reactivated, it shouldn't be much different to do the same if we personally ban someone from our own channel.