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 commentJannek commented
There is a tool by CommanderRoot.